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Recommendations for Quantification of Doppler Echocardiography: A Report From the Doppler Quantification Task Force of the Nomenclature and Standards Committee of the American Society of Echocardiography
... The rationale behind measuring 3-10 mm below the annulus is based on the requirement for the pulsed Doppler sample volume to be in the same anatomic plane where the cross-sectional area is calculated for accurate continuity equation results. Therefore, when obtaining the LVOT velocity in the presence of AS, if the Doppler cursor is backed away from the aortic valve, to avoid pre-valvular acceleration, then the location of 2D LVOT measurement in parasternal long must also be backed away from the aortic valve as well [22]. ...
... to be in the same anatomic plane where the cross-sectional area is calculated for accurate continuity equation results. Therefore, when obtaining the LVOT velocity in the presence of AS, if the Doppler cursor is backed away from the aortic valve, to avoid pre-valvular acceleration, then the location of 2D LVOT measurement in parasternal long must also be backed away from the aortic valve as well [22]. Aortic morphology and movement. ...
... The machine operator must ensure that the Doppler signal is large enough to measure accurately the blood velocity in that specific cardiac depth; the velocity curve should be smooth and have a dense outer edge to be measured, and the small, fine, linear signals should be excluded. LVOT spectral Doppler velocity time integral (VTI) assessment with the sample volume in a wrong position or being too large, with too high gain or too high wall filter settings, low sweep speed, and baseline inappropriately low [22,41]. The LVOT VTI is recorded from an apical approach, using either an anteriorly angulated four-chamber view or positioning the sample volume of pulsed Doppler proximal to the region of blood flow acceleration in the LVOT (Figure 8). ...
Aortic stenosis (AS) is a valvular heart disease that significantly contributes to cardiovascular morbidity and mortality worldwide. The condition is characterized by calcification and thickening of the aortic valve leaflets, resulting in a narrowed orifice and increased pressure gradient across the valve. AS typically progresses from a subclinical phase known as aortic sclerosis, where valve calcification occurs without a transvalvular gradient, to a more advanced stage marked by a triad of symptoms: heart failure, syncope, and angina. Echocardiography plays a crucial role in the diagnosis and evaluation of AS, serving as the primary non-invasive imaging modality. However, to minimize misdiagnoses, it is crucial to adhere to a standardized protocol for acquiring echocardiographic images. This is because, despite continuous advances in echocardiographic technology, diagnostic errors still occur during the evaluation of AS, particularly in classifying its severity and hemodynamic characteristics. This review focuses on providing guidance for the imager during the echocardiographic assessment of AS. Firstly, the review will report on how the echo machine should be set to improve image quality and reduce noise and artifacts. Thereafter, the review will report specific emphasis on accurate measurements of left ventricular outflow tract diameter, aortic valve morphology and movement, as well as aortic and left ventricular outflow tract velocities. By considering these key factors, clinicians can ensure consistency and accuracy in the evaluation of AS using echocardiography.
... Two-dimensional transthoracic echocardiography (TTE) and the Doppler study were performed according to the Guidelines of the American Society of Echocardiography [7,8] . The thickness of the interventricular septum (IVST), the thickness of the posterior wall (PWT), and the diastolic diameter of the left ventricular (LVDD) were measured in the telediastole; the left ventricle systolic diameter (LVSD) on the telesystole. ...
... The left ventricular ejection fraction (LVEF) was calculated by the Simpson method. The left ventricular systolic function was classified into 4 types: preserved if LVEF ≥55%, slightly compromised if LVEF was between 45-54%, moderately compromised if LVEF is between 30-44% and severely compromised if LVEF <30% [7] . Left ventricular filling was assessed by recording mitral flow by standard pulse Doppler technique, and the following parameters were considered: early diastolic peak flow velocity (E), late diastolic peak flow velocity (A) and the ratio of the early to late flow velocity peaks (E/A ratio) ( fig 1B). ...
... The peak systolic and diastolic velocities were measured at a sweep speed of 100 mm/s. 17 Isovolumetric relaxation time (IVRT), isovolumetric contraction time (IVCT), and ET were calculated based on the TDI results. MPI was calculated according to the Tei method by dividing the sum of IVCT and IVRT by ET 8 (figure 1). ...
Introduction
Oxidative stress is known to affect left ventricular functions negatively. There is a strong bidirectional connection between diabetes mellitus (DM) and oxidative stress. In parallel, left ventricular dysfunction is observed more frequently, even in patients with DM without other risk factors. In this context, the objective of this study is to comparatively investigate the potential relationship between oxidative stress and subclinical left ventricular dysfunction (SCLVD) assessed by Myocardial Performance Index (MPI) in patients with and without DM.
Research design and methods
The sample of this observational cross-sectional single-center study consisted of 151 patients who were evaluated for oxidative stress and SCLVD by tissue Doppler echocardiography. Patients’ total oxidant status (TOS), total antioxidant status (TAS), and Oxidative Stress Index (OSI) values were calculated. The effects of oxidative stress and DM on MPI were analyzed.
Results
There were 81 patients with DM (mean age: 46.17±10.33 years) and 70 healthy individuals (mean age: 45.72±9.04 years). Mean TOS and OSI values of the DM group were higher than healthy individuals (5.72±0.55 vs 5.31±0.50, p = <0.001; and 4.92±1.93 vs 1.79±0.39, p = <0.001; respectively). The mean TAS value of the DM group was significantly lower than the healthy group (1.21±0.40 vs 3.23±0.51, p = <0.001). There was a significant correlation between OSI and MPI mitral in the DM group (R 0.554, p = <0.001) but not in the healthy group (R −0.069, p=0.249).
Conclusions
Both oxidative stress and myocardial dysfunction were found to be more common in patients with DM. The study’s findings indicated the negative effect of oxidative stress on myocardial functions. Accordingly, increased oxidative stress caused more significant deterioration in MPI in patients with DM compared with healthy individuals.
... assessment of patients with pulmonary hypertension, cardiogenic shock, and unexplained dyspnea) [7], TTE has become the primary imaging modality for assessing cardiac function in routine clinical settings because of its non-invasiveness, widespread use, portability, affordability, and safety (no ionized radiation) [8]. Consequently, TTE is considered as the established standard for daily clinical practice in the assessment of SV and CO [9,10]. ...
Background
In cardiology, cardiac output (CO) is an important parameter for assessing cardiac function. While invasive thermodilution procedures are the gold standard for CO assessment, transthoracic Doppler echocardiography (TTE) has become the established method for routine CO assessment in daily clinical practice. However, a demand persists for non-invasive approaches, including oscillometric pulse wave analysis (PWA), to enhance the accuracy of CO estimation, reduce complications associated with invasive procedures, and facilitate its application in non-intensive care settings. Here, we aimed to compare the TTE and oscillometric PWA algorithm Antares for a non-invasive estimation of CO.
Methods
Non-invasive CO data obtained by two-dimensional TTE were compared with those from an oscillometric blood pressure device (custo med GmbH, Ottobrunn, Germany) using the integrated algorithm Antares (Redwave Medical GmbH, Jena, Germany). In total, 59 patients undergoing elective cardiac catheterization for clinical reasons (71±10 years old, 76% males) were included. Agreement between both CO measures were assessed by Bland-Altman analysis, Student’s t-test, and Pearson correlations.
Results
The mean difference in CO was 0.04 ± 1.03 l/min (95% confidence interval for the mean difference: -0.23 to 0.30 l/min) for the overall group, with lower and upper limits of agreement at -1.98 and 2.05 l/min, respectively. There was no statistically significant difference in means between both CO measures (P = 0.785). Statistically significant correlations between TTE and Antares CO were observed in the entire cohort (r = 0.705, P<0.001) as well as in female (r = 0.802, P<0.001) and male patients (r = 0.669, P<0.001).
Conclusions
The oscillometric PWA algorithm Antares and established TTE for a non-invasive estimation of CO are highly correlated in male and female patients, with no statistically significant difference between both approaches. Future validation studies of the Antares CO are necessary before a clinical application can be considered.
... With the images obtained through PW Doppler and tissue Doppler echocardiography examinations, the following parameters were measured: E wave velocity, A wave velocity, E/A ratio, E/E' ratio, ejection time (ET), isovolumetric relaxation time (IVRT), isovolumetric contraction time (IVCT), and myocardial performance index (MPI). An MPI value 0.45 was considered within the normal range [7,8]. ...
Our aim in this study is to evaluate the cardiovascular findings of pediatric patients with primary Raynaud’s phenomenon (RP) and to determine if there are any pathological findings. Our study included 42 pediatric patients aged between 7 and 18 who were diagnosed with primary RP and did not have any additional underlying structural vascular disease or secondary rheumatological conditions. The control group consisted of 30 healthy volunteers aged 7–18 years, matched by age and sex, without any additional diseases. We evaluated demographic, clinical, and laboratory findings, echocardiographic and capillaroscopic features, as well as carotid intima-media thickness. Compared to the control group, pediatric patients with primary RP showed increased A wave velocity and E/E' ratio parameters in the left ventricle, indicating diastolic dysfunction of the heart. The isovolumetric relaxation time (IVRT) was prolonged in both the left and right ventricles, and the E/A ratio decreased in the left ventricle. The myocardial performance index (MPI), indicating both systolic and diastolic dysfunction, increased in both ventricles. Additionally, the aortic stiffness index, aortic elastic modulus (Ep), and left carotid intima-media thickness (CIMT) significantly increased, while distensibility decreased in pediatric patients with primary RP compared to the control group. The cardiovascular evaluation of pediatric patients with primary RP revealed that diastolic dysfunction is likely present in both the left and right heart. Additionally, based on the aorta and carotid intima measurements, it is suggested that pediatric patients with primary RP are at risk for developing atherosclerosis.
... 3. Freeze the image and decrease overall gain to optimize the borders of the waveform [25]. 4. Trace the outer edge of the dense waveform using the VTI tracing function, ensuring exclusion of any overgained areas or spectral dispersion that often occurs near peak velocity [26]. ...
Purpose of Review
To review the tests of fluid responsiveness and volume status with critical care echocardiography, including their uses, performance, and limitations.
Recent Findings
Fluid overload is detrimental to critically ill patients. Dynamic parameters of fluid responsiveness are able to predict which patients will respond to a fluid bolus with an increase in cardiac output. These tests include the passive leg raise, stroke volume variation, vena cava variability, and the end expiratory occlusion maneuver.
Summary
Critical care echocardiography can be used to evaluate changes in preload and stroke volume during performance of dynamic fluid responsiveness tests. The LVOT VTI is a central parameter used to estimate changes in stroke volume in real time during performance of these tests.
... Diagnostic US imaging methods include a brightness mode (B-mode) that expresses the intensity of the echo in grayscale and a motion mode (M-mode) that detects temporal motion. In addition, there are color and power Doppler modes that visualize blood flow direction and speed information using the color spectrum, and each method facilitates clinical diagnosis according to the purpose of the examination [10][11][12]. ...
In ultrasound diagnostics, acoustic absorbers block unwanted acoustic energy or prevent the reception of echo signals from structures outside the target area. Non-metallic absorbers provide a low-echoic signal that is suitable for observing the anatomy of the area to which the absorber is attached. In this study, we aimed to evaluate the effect of a polyurethane film absorber (PU) on ultrasound diagnostic imaging and investigate its effectiveness in improving the image contrast between the fascia and muscle structures. Twenty-six healthy men in their twenties participated in this study. The experiment was performed with the participant in the supine position and with an ultrasound transducer probe placed at the center of the measurement area on the abdomen. Images of the rectus abdominis (RA; muscle) and rectus sheath, e.g., fascia including superficial fascia (SF) and deep fascia (DF), obtained after attaching a PU, were compared with those obtained without the absorber (No_PU). The thickness was measured using brightness mode ultrasound imaging. To analyze the quantitative differences in the fascia and muscle images depending on the presence of the absorber, the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were derived from the signal intensities measured in the target areas. The thickness of the fascia and muscle was similar in all regions of interest, regardless of the absorber; therefore, the existing diagnostic value was maintained. Overall, the signal intensity decreased; however, the SNRs of the RA, SF, and DF differed significantly. The SNR of the RA decreased in the PU but increased for the SF and DF. The CNRs for SF-RA and DF-RA significantly increased with the PU. In this study, we demonstrated that the PU behaved similarly to previously used metallic absorbers, reducing the signal from the attachment site while accurately indicating the attachment site in the ultrasound images. Furthermore, the results showed that the PU efficiently distinguished fascia from surrounding tissues, which could support studies requiring increased signal contrast between fascia and muscle tissue and aid the clinical diagnosis of fascial diseases.
... According to guidelines from the American Society of Echocardiography (ASE), the biplane method of discs for ejection fraction (EF) quantification is preferred [14,15]. These measurements were expressed as Z-score values adjusted for body surface area as compared with the normal pediatric population [16,17]. For deformation analysis, endocardial borders were traced at the end-diastolic frame in apical views. ...
Dilated cardiomyopathy (DCM) is the most common childhood cardiomyopathy and is associated with considerable early mortality. Heart transplantation is often the only viable life-saving option. Pulmonary artery banding (PAB) has been recently proposed as a bridge or alternative to transplantation for DCM. In our cohort, PAB was selectively addressed to heritable DCM or DCM with congenital left ventricle aneurysm (CLVA). This study aimed to describe the clinical evolution and left ventricle reverse remodeling (LVRR) over time (6 months and 1 year after surgery). Ten patients with severe DCM received PAB between 2016 and 2021 and underwent clinical and postoperative echocardiography follow-ups. The median age at PAB was <1 year. The in-hospital mortality was zero. Two patients died two months after PAB of end-stage heart failure. The modified Ross class was improved in the eight survivors with DCM and remained stable in the two patients with CLVA. We observed a positive LVRR (LV end-diastolic diameter Z-score: 8.4 ± 3.7 vs. 2.8 ± 3; p < 0.05; LV ejection fraction: 23.8 ± 5.8 to 44.5 ± 13.1 (p < 0.05)). PAB might be useful as part of the armamentarium available in infants and toddlers with severe DCM not sufficiently responding to medical treatment with limited probability of spontaneous recovery.
... Three electrocardiographic leads were used to obtain a simultaneous display during the examination. All measurements and calculations were taken in three or five consecutive cardiac cycles and were followed according to the recommendations of the latest American and European Societies Guidelines for echocardiographic assessment, [9][10][11] as previously reported. 5,6 Analysing the motion of speckles in the 2D ultrasonic image by STE, we assessed myocardial deformation and quantified myocardial thickening, shortening, and the rotation dynamics of the LV, 12 using a speckle-tracking algorithm provided by Hitachi-ALOKA. ...
Aims
There is little information from experimental studies regarding the evolution of post-resuscitation cardiac arrest [post-return of spontaneous circulation (post-ROSC)] myocardial dysfunction during mid-term follow-up. For this purpose, we assessed left ventricular (LV) function and circulating cardiac biomarkers at different time points in a rat model of cardiac arrest (CA).
Methods and results
Rats were divided into two groups: control and post-ROSC rats. Eight minutes of untreated ventricular fibrillation were followed by 8 min of cardiopulmonary resuscitation. Conventional and speckle-tracking echocardiographic (STE) parameters and cardiac circulating biomarkers concentrations were assessed, at 3, 4, 72, and 96 h post-ROSC. At 3 and 4 h post-ROSC, LV systolic function was severely impaired, and high-sensitivity cardiac troponin T and N-terminal pro-atrial natriuretic peptide (NT-proANP) plasma concentrations were significantly increased, compared with control rats (P < 0.0001 for all). At 72 and 96 h post-ROSC, LV ejection fraction (LVEF) normalized. At 96 h, the following variables were significantly different from control rats: early trans-mitral peak velocity, 56.8 ± 3.1 vs. 87.8 ± 3.8 cm/s, P < 0.0001; late trans-mitral peak velocity, 50.6 ± 4.7 vs. 73.7 ± 4.2 cm/s, P < 0.0001; mean s′ wave velocity, 4.6 ± 0.3 vs. 5.9 ± 0.3 cm/s, P < 0.0001, global longitudinal strain (GLS) −7.5 ± 0.5 and vs. −11 ± 1.2%, P < 0.01; GLS rate (GLSR) −0.9 ± 0.4 and −2.3 ± 0.2 1/s, P < 0.01; and NT-proANP concentration, 2.5 (0.2; 6.0) vs. 0.4 (0.01; 1.0) nmol/L, P < 0.01.
Conclusion
s′ velocity, GLS, and GLSR indicated that LV systolic function was still impaired 96 h post-ROSC. These findings agree with NT-proANP concentrations, which continue to be high. Normalization of LVEF supports the use of STE for its greater sensitivity for monitoring post-CA cardiac function. Further investigations are needed to provide evidence of the post-ROSC LV diastolic function pattern.
... All measurements were made using a GE Vivid i Ultrasound (GE healthcare, Nanjing, China) with a 2-5 MHz cardiac transducer and were performed by a single researcher. Participants underwent an echocardiogram using the parasternal long axis view to assess LVM according to the American Society of Echocardiography [49,50]. As previously reported by our laboratory [1], the parasternal long axis view was obtained with the probe placed near the 3rd intercostal space adjacent to the sternum. ...
Exercise is a major modifiable lifestyle factor that leads to temporarily increased systolic blood pressure (SBP), which is thought to influence left ventricular mass normalized to body surface area (LVM/BSA). This relationship has never been studied in women who habitually perform resistance exercise. Purpose: To determine if a direct correlation exists between the SBP response to resistance exercise (change from rest; eSBP) and LVM/BSA in young healthy women who habitually resistance train. Methods: Leg extension resistance exercise was performed while continuously monitoring blood pressure using finger plethysmography. LVM was estimated using echocardiography. Data are shown as mean ± SD. Results: Thirty-one women participated (age 23 ± 3 years, height 164 ± 7 cm, body mass 63.7 ± 10.3 kg). Resting SBP (110 ± 8 mmHg, r = 0.355, p = 0.049) was shown to be directly correlated to LVM/BSA (72.0 ± 28.4 g/m2). Conversely, eSBP (30.8 ± 14.6 ∆mmHg, r = −0.437, p = 0.014) was inversely related to LVM/BSA. eSBP was not correlated to interventricular septum width (0.88 ± 0.12 cm, r = −0.137, p = 0.463) or posterior wall thickness (0.91 ± 0.15 cm, r = −0.084, p = 0.654). eSBP was inversely related to left ventricle internal diameter during diastole (LVIDd) (4.25 ± 0.33 cm, r = −0.411, p = 0.021). Conclusion: Counter to the hypothesis, these data suggest an inverse association between eSBP during resistance exercise and LVM/BSA in healthy young women who resistance train. This relationship is due to a smaller LVIDd with greater eSBP.
... Conventional echocardiographic parameters, e.g., relative wall thickness (RWT), LV mass index (LVMi), LVEF, and cardiac index (CI) were determined by 2D and Doppler echocardiography according to current guidelines and recommended reference values were applied (17)(18)(19). All components of LV deformation were analyzed. ...
Purpose
Cardiac magnetic resonance imaging (cMRI) represents the gold standard to detect myocarditis. Left ventricular (LV) deformation imaging provides additional diagnostic options presumably exceeding conventional transthoracic echocardiography (TTE). The present study aimed to analyze the feasibility to detect myocarditis in patients (pts) with preserved LV ejection fraction (LVEF) by TTE compared to cMRI. It has been hypothesized that the number of pathological findings by deformation imaging correspond to findings in cMRI.
Methods and results
Between January 2018 and February 2020 102 pts with acute myocarditis according to the modified Lake Louise criteria and early gadolinium enhancement (EGE) by cMRI were identified at the department of cardiology at the University Hospital Leipzig. Twenty-six pts were included in this retrospective comparative study based on specific selection criteria. Twelve pts with normal cMRI served as a control group. LV deformation was analyzed by global and regional longitudinal strain (GLS, rLS), global and regional circumferential and radial strain (GCS, rCS, GRS, rRS), and LV rotation (including layer strain analysis). All parameters were compared to findings of edema, inflammation, and fibrosis by cMRI according to Lake Louise criteria. All pts with acute myocarditis diagnosed by cMRI showed pathological findings in TTE. Especially rCS and LV rotation analyzed by regional layer strain exhibit a high concordance with pathological findings in cMRI. In controls no LV deformation abnormalities were documented. Mean values of GLS, GRS, and GCS were not significantly different between pts with acute myocarditis and controls.
Conclusion
This retrospective analysis documents the feasibility of detecting regional deformation abnormalities by echocardiography in patients with acute myocarditis confirmed by cMRI. The detection of pathological findings due to myocarditis requires the determination of regional deformation parameters, particularly rCS and LV rotation. The assessment of global strain values does not appear to be of critical value.
... In the interpretation of the results, measurement errors of the imaging modalities must be considered. According to Quiniones et al. [39], velocity measurements in PW-Doppler acquisitions, can produce errors of up to 10 % already at small differences in the angle. In 4D flow MRI, the errors can be up to 5 % at a velocity-encoding of 200 cm/s [27]. ...
Computational fluid dynamics (CFD) carry the potential to provide detailed insights into intraventricular hemodynamics and complement in vivo flow measurement techniques. A variety of CFD approaches emerged in recent years, mostly building solely on medical image data as patient‐specific input. While the utilized medical imaging method and chosen CFD approach both influence the computed hemodynamics, thereto related differences are rarely investigated. The present study addresses this issue with an inter‐(imaging)‐modality and inter‐model comparison of intracardiac flow computations. Magnetic resonance imaging (MRI) and transthoracic echocardiography (TTE) data of a volunteer were acquired and used to reconstruct the anatomical structures. For each modality, the reconstructed shapes were applied in two previously introduced CFD approaches to compute whole‐cycle ventricular flow patterns. While both methods involved benefits and challenges, similar valve velocities were computed, being in accordance with in vivo 4D flow MRI and pulsed‐wave Doppler velocity measurements (systolic peak velocity: 1.24–1.26 m/s (MRI), 0.9–1.25 m/s (TTE); diastolic peak velocity: 0.54 m/s (MRI), 0.59–0.75 m/s (TTE)). A detailed flow analysis with vortex formation, kinetic energy, and mid‐ventricular velocities indicated the computed inter‐modality differences to be larger than inter‐method ones. Quantitatively, this could be observed in the direct flow rate ( inter‐modality: 13, inter‐method, 3). These results help to gain trust in CFD approaches to compute intraventricular flow and emphasize the importance of standardized input data. Future studies, however, should consider a broader data base.
... Transthoracic echocardiography (TTE) providing color Doppler echocardiography images is the most important imaging method for valvular regurgitation diagnosis and evaluation due to its widespread availability, non-invasiveness, low cost, acceptability, and safety profile [1]. TTE color Doppler echocardiography images provides information of cardiac structure, function, and hemodynamics and has a high sensitivity and specificity in assessing the flow of blood through the heart valves. ...
This study investigated the automatic segmentation and classification of mitral regurgitation (MR) and tricuspid regurgitation (TR) using a deep learning-based method, aiming to improve the efficiency and accuracy of diagnosis of valvular regurgitations. A VABC-UNet model was proposed consisting of VGG16 encoder, U-Net decoder, batch normalization, attention block and deepened convolution layer based on the U-Net backbone. Then, a VABC-UNet-based assessment framework was established for automatic segmentation, classification, and evaluation of valvular regurgitations. A total of 315 color Doppler echocardiography images of MR and/or TR in an apical four-chamber view were collected, including 35 images in the test dataset and 280 images in the training dataset. In comparison with the classic U-Net and VGG16-UNet models, the segmentation performance of the VABC-UNet model was evaluated via four metrics: Dice, Jaccard, Precision, and Recall. According to the features of regurgitation jet and atrium, the regurgitation could automatically be classified into MR or TR, and evaluated to mild, moderate, moderate–severe, or severe grade by the framework. The results show that the VABC-UNet model has a superior performance in the segmentation of valvular regurgitation jets and atria to the other two models and consequently a higher accuracy of classification and evaluation. There were fewer pseudo- and over-segmentations by the VABC-UNet model and the values of the metrics significantly improved (p < 0.05). The proposed VABC-UNet-based framework achieves automatic segmentation, classification, and evaluation of MR and TR, having potential to assist radiologists in clinical decision making of the regurgitations in valvular heart diseases.
... All patients underwent transthoracic echocardiography, performed using a Vivid 7 Dimension Cardiovascular Ultrasound System, (GE Medical Systems, USA), before the cryoballoon ablation procedure and echocardiographic measurements were made according to the criteria recommended by the American Echocardiography Society. 18 All patients also underwent transesophageal echocardiography within 48 h before the procedure to exclude a left atrium thrombus that was defi ned as an echogenic mass in the left atrial appendage that continued into more than one plane and could be clearly distinguished from surrounding tissue; patients with thrombus in the left atrial appendage were excluded. Anticoagulants were discontinued at least 48-72 h before the procedure, and enoxaparin (1 mg/kg) was initiated if INR was <2 in the interim. ...
... To solve this, CW Doppler mode is used that contains two crystals, one for sending and one for receiving ultrasound waves continuously (11,12). In medical utilization, direction and velocity of blood flow is displayed in colors: blue for blood flow direction away from transducer and red for blood flow toward transducer, conventionally (13,14). In this article we introduce a new approach to display and analyze color Doppler M-mode echocardiography of Descending aorta. ...
M-mode echocardiography is one of the basic modes of ultrasound imaging that is generally used in echocardiography. In this article we introduce a new approach to display three and four dimensional color M-mode echocardiography.
... Measurements were obtained in M-mode and Doppler (scanning at 100 or 150 mm/s). Measurements were conducted according to the principles accepted by the American Society of Echocardiography (Quiñones et al. 2002). The rats were anesthetized with ketamine (45 mg/kg) and xylazine (5 mg/kg) intraperitoneally. ...
Cardiac hypertrophy (CH) is an adaptational enlargement of the myocardium, in exposure to altered stress conditions or in case of injury which can lead to heart failure and death. MicroRNAs (miRNAs) are non-coding RNAs that play a significant role in modulating gene expression. Here, we aimed to identify new miRNAs effective in an experimental CH model and to find an epigenetic biomarker that could demonstrate therapeutic targets responsible for the pathology of heart tissue and serum. In this study, Sprague–Dawley male rats were divided into the training group (TG, n=9) and the control group (CG, n=6). Systolic and diastolic dimensions of the left ventricle and myocardial wall thickness were measured by echocardiography to assess CH. After the exercise program of the rats, miRNA expression measurements and histological analyses were performed. The 25,000 genes in the rat genome were searched using microarray analysis. A total of 128 miRNAs were selected according to the fold change rates, and nine miRNAs were validated for expression analysis. The terminal deoxynucleotidyl transferase dUTP nick (TUNEL) method was used to detect apoptotic cells. Cell proliferation was evaluated by the proliferative cell nuclear antigen (PCNA) method. Necrosis, bleeding, and intercellular edema were detected in TG. The mean histopathological score was higher in TG (p=0.03). There were rarely positive cells for apoptosis of both groups in cardiomyocytes. In the receiver characteristic curve analysis (ROC), the heart tissue rno-miR-290 had an area under the curve (AUC) of 0.920 with 100% sensitivity and 89.90% specificity (p=0.045), rno-miR-194-5p had AUC of 0.940 with 83.33% sensitivity and 100% specificity (p=0.003), and the serum rno-miR-132-3p AUC was 0.880 with 66.67% sensitivity and 100% specificity (p=0.004) in TG. miR-194-5p was used as a therapeutic target for remodeling the cardiac process. While miR-290 contributes to CH as a negative regulator, miR-132 in serum is effective in the pathological and physiological cardiac remodeling process and is a candidate biomarker.
... The patient was diagnosed as having heart failure according to the recommendation of the European Society of Cardiology (8) , depending on the result of history, examination and echocardiographic conformation. For all subjects, a Doppler and 2D echocardiographic measurements were performed according to the recommendations of the American Society of Echocardiography (9)(10)(11) . All echocardiographic measurements were performed by using GE Vivid 3 echocardiographic machine provided by GE company-USA. ...
Heart failure is the failure of the cardiac pump under physiological loading conditions to impart sufficient hydraulic energy output in order to maintain a physiological circulation. A cohort study extended over a period of 14 months from the first of august 2010 to the first of November 2011. The patient was diagnosed as having heart failure according to the recommendation of the European Society of Cardiology, depending on the result of history, examination and echocardiographic conformation. Spirometric data were collected in accordance with American Thoracic Society standards. All the patients had a restrictive spirometric defect before treatment with diuretics, but after treatment all show normal spirometric pattern. The present study recommend the followings: - The use of a cheap office spirometer in rural area by general practitioner (GP) doctors and nursing staff could be useful for follow up patients with ischemic heart failure to detect early deterioration by objective mean to refer the patient for specialized care. Also, the office spirometer needs no special skills and the nursing staff can master the procedure with a 2 weeks training course.
... Dogs were not considered if they showed one or more of the following criteria: a) heart murmur, gallop sound, or electrocardiographic abnormality; b) recent or current evidence of systemic illness based on history or physical examination (except brachycephalic obstructive airway syndrome given the predisposition of this breed to such condition); c) ongoing medications affecting the cardiovascular system; d) lack of cooperation during the echocardiographic examination, leading to suboptimal image acquisition; e) females that were in estrus, pregnant, or lactating; or e) significant cardiac abnormalities identified on two-dimensional (2D), M-Mode, and/or Doppler mode. For this study, trivial valve regurgitations (i.e., barely detectable jets of a few discrete color pixels close to the valvular coaptation point not always detectable throughout systole (in the case of mitral or tricuspid regurgitation) or diastole (in the case of aortic or pulmonary regurgitation) associated neither with audible murmurs on cardiac auscultation nor with any structural valve abnormalities on echocardiography were considered clinically nonsignificant, and these dogs were not excluded from the study (Rishniw and Erb, 2000a;Quiñones et al., 2002;Zoghbi et al., 2003). With specific concern to echocardiography, all examinations were performed by a board-certified cardiologist (G. ...
Background
Transthoracic echocardiography represents the main noninvasive technique for evaluating cardiac morphology and function in dogs. In dogs with particular somatotypes, such as brachymorphic dogs, breed-specific echocardiographic values are needed for a proper echocardiographic interpretation. Nowadays, the Pug represents one of the most popular brachymorphic canine breeds worldwide. However, data on echocardiographic measurements in this breed are currently limited.
Aim
We aimed to determine echocardiographic values in a population of apparently healthy Pugs, and to assess the possible effects of body weight (BW), age, and sex on selected echocardiographic variables, with particular emphasis on those related to the left-sided cardiac chambers.
Methods
Apparently healthy Pugs underwent a full physical examination, a 1-minute six-lead electrocardiogram, and a complete transthoracic echocardiography. Twenty-four echocardiographic variables were measured by combining M-mode, two-dimensional and Doppler modalities, and relative values were determined by applying the statistical procedures recommended by the Clinical and Laboratory Standards Institute. Moreover, the effect of selected demographic variables on echocardiographic measurements was tested using a linear mixed model.
Results
The investigation included 86 Pugs. Echocardiographic values were provided for each variable and compared with previous veterinary literature. A statistically significant effect of BW, age, and sex was documented for several of the tested variables. Doppler examination demonstrated a trivial pulmonary regurgitation in 24/86 (27.9%) Pugs. Moreover, a persistent left cranial vena cava was suspected in 4/86 (4.7%) dogs.
Conclusion
Echocardiographic features of the Pug were addressed and echocardiographic values were made available for clinical use. Because our findings were obtained using a standardized echocardiographic analysis in a population of 86 healthy Pugs, they may act as a reliable guide for an accurate echocardiographic interpretation in this breed.
... Functional analysis of echocardiograms was performed by the same reader (JHS) based on American Society of Echocardiography guidelines and consisted of: (1) left ventricular chamber dimensions and corresponding z-scores measured on M-mode images in the short axis at the level of the papillary muscles; (2) fractional shortening calculated from the left ventricular internal dimensions in systole and diastole; (3) left ventricular ejection fraction (LVEF) measured using the 5/6 area length method from the short axis at the level of the papillary muscles and the apical four-chamber views; (4) left atrial dimension and corresponding z-score measured in the long axis on two-dimensional imaging; (5) mitral E and A wave velocities; and (6) E 0 tissue Doppler velocities measured at the septum and free wall. [24][25][26][27] Biomarker analysis BDNF was measured from serum using the Quantikine BDNF enzyme-linked immunosorbent assay (ELISA) kit (R&D systems, Minneapolis, Minnesota, USA; catalog no. DBD00). ...
... The images were obtained with a CX 50 Ultrasound System (Philips ® , Bothell, United States of America), using a 5 to 1 MHz sector array transducer, and analyzed after the examination on the same system by the same physicians. A standard echocardiographic investigation was performed according to guidelines (Quiñones et al., 2002;Rudski et al., 2010;Lang et al., 2015). ...
Background: Asthma rehabilitation at high altitude is common. Little is known about the acute and subacute cardiopulmonary acclimatization to high altitude in middle-aged asthmatics without other comorbidities.
Methods: In this prospective study in lowlander subjects with mostly mild asthma who revealed an asthma control questionnaire score >0.75 and participated in a three-week rehabilitation program, we assessed systolic pulmonary artery pressure (sPAP), cardiac function, and extravascular lung water (EVLW) at 760 m (baseline) by Doppler-echocardiography and on the second (acute) and last day (subacute) at a high altitude clinic in Kyrgyzstan (3100 m).
Results: The study included 22 patients (eight male) with a mean age of 44.3 ± 12.4 years, body mass index of 25.8 ± 4.7 kg/m ² , a forced expiratory volume in 1 s of 92% ± 19% predicted (post-bronchodilator), and partially uncontrolled asthma. sPAP increased from 21.8 mmHg by mean difference by 7.5 [95% confidence interval 3.9 to 10.5] mmHg ( p < 0.001) during acute exposure and by 4.8 [1.0 to 8.6] mmHg ( p = 0.014) during subacute exposure. The right-ventricular-to-pulmonary-artery coupling expressed by TAPSE/sPAP decreased from 1.1 by −0.2 [−0.3 to −0.1] mm/mmHg ( p < 0.001) during acute exposure and by −0.2 [−0.3 to −0.1] mm/mmHg ( p = 0.002) during subacute exposure, accordingly. EVLW significantly increased from baseline (1.3 ± 1.8) to acute hypoxia (5.5 ± 3.5, p < 0.001) but showed no difference after 3 weeks (2.0 ± 1.8).
Conclusion: In otherwise healthy asthmatics, acute exposure to hypoxia at high altitude increases pulmonary artery pressure (PAP) and EVLW. During subacute exposure, PAP remains increased, but EVLW returns to baseline values, suggesting compensatory mechanisms that contribute to EVLW homeostasis during acclimatization.
BACKGROUND
Hypertrophic cardiomyopathy (HCM) is defined clinically by pathological left ventricular hypertrophy. We have previously developed a plasma proteomics biomarker panel that correlates with clinical markers of disease severity and sudden cardiac death risk in adult patients with HCM. The aim of this study was to investigate the utility of adult biomarkers and perform new discoveries in proteomics in childhood-onset HCM.
METHODS
Fifty-nine protein biomarkers were identified from an exploratory plasma proteomics screen in children with HCM and augmented into our existing multiplexed targeted liquid chromatography-tandem/mass spectrometry-based assay. The association of these biomarkers with clinical phenotypes and outcomes was prospectively tested in plasma collected from 148 children with HCM and 50 healthy controls. Machine learning techniques were used to develop novel pediatric plasma proteomic biomarker panels.
RESULTS
Four previously identified adult HCM markers (aldolase fructose-bisphosphate A, complement C3a, talin-1, and thrombospondin 1) and 3 new markers (glycogen phosphorylase B, lipoprotein a, and profilin 1) were elevated in pediatric HCM. Using supervised machine learning applied to training (n=137) and validation cohorts (n=61), this 7-biomarker panel differentiated HCM from healthy controls with an area under the curve of 1.0 in the training data set (sensitivity 100% [95% CI, 95–100]; specificity 100% [95% CI, 96–100]) and 0.82 in the validation data set (sensitivity 75% [95% CI, 59–86]; specificity 88% [95% CI, 75–94]). Reduced circulating levels of 4 other peptides (apolipoprotein L1, complement 5b, immunoglobulin heavy constant epsilon, and serum amyloid A4 peptides) found in children with high sudden cardiac death risk provided complete separation from the low and intermediate risk groups and predicted mortality and adverse arrhythmic outcomes (hazard ratio, 2.04 [95% CI, 1.0–4.2]; P =0.044).
CONCLUSIONS
In children, a 7-biomarker proteomics panel can distinguish HCM from controls with high sensitivity and specificity, and a second 4-biomarker panel identifies those at high risk of adverse arrhythmic outcomes, including sudden cardiac death.
Efforts have been made over the last five decades to create effective ultrasonic contrast media (UCM) for cardiac and noncardiac applications. The initial UCM was established in the 1980s, following publications from the 1960s that detailed the discovery of ultrasonic contrast enhancement using small gaseous bubbles in echocardiographic examinations. An optimal contrast agent for echography should possess the following characteristics: non-toxicity, suitability for intravenous injection, ability to traverse pulmonary, cardiac, and capillary circulations, and stability for recirculation. Definity, Optison, Sonazoid, and SonoVue are examples of current commercial contrast media. These contrast media have shown potential for various clinical reasons, both on-label and off-label. Several possible UCMs have been developed or are in progress. Advancements in comprehending the physical, chemical, and biological characteristics of microbubbles have significantly improved the visualization of tumor blood vessels, the identification of areas with reduced blood supply, and the enhanced detection of narrowed blood vessels. Innovative advances are expected to enhance future applications such as ultrasonic molecular imaging and therapeutic utilization of microbubbles.
Background
Data using real‐world assessments of aortic regurgitation (AR) severity to identify rates of Heart Valve Team evaluation and aortic valve replacement (AVR), as well as mortality among untreated patients, are lacking. The present study assessed these trends in care and outcomes for real‐world patients with documented AR.
Methods
Using a deidentified data set (January 2018–March 2023) representing 1,002,853 patients >18 years of age from 25 US institutions participating in the egnite Database (egnite, Inc.) with appropriate permissions, patients were classified by AR severity in echocardiographic reports. Rates of evaluation by the Heart Valve Team, AVR, and all‐cause mortality without AVR were examined using Kaplan–Meier estimates and compared using the log‐rank test.
Results
Within the data set, 845,113 patients had AR severity documented. For moderate‐to‐severe or severe AR, respectively, 2‐year rates (95% confidence interval) of evaluation by the Heart Valve Team (43.5% [41.7%–45.3%] and 65.4% [63.3%–67.4%]) and AVR (19.4% [17.6%–21.1%] and 46.5% [44.2%–48.8%]) were low. Mortality at 2 years without AVR increased with greater AR severity, up to 20.7% for severe AR ( p < 0.001). In exploratory analyses, 2‐year mortality for untreated patients with left ventricular end‐systolic dimension index > 25 mm/m ² was similar for moderate (34.3% [29.2%–39.1%]) and severe (37.2% [24.9%–47.5%]) AR.
Conclusions
Moderate or greater AR is associated with poor clinical outcomes among untreated patients at 2 years. Rates of Heart Valve Team evaluation and AVR were low for those with moderate or greater AR, suggesting that earlier referral to the Heart Valve Team could be beneficial.
Background
The burden of screening for inherited cardiac conditions on health services grows ever larger, with each new diagnosis necessitating screening of additional family members. Screening these usually asymptomatic, low-risk individuals is currently performed by consultant cardiologists, consuming vital clinic resources that could otherwise be diverted to sicker patients requiring specialist consultant input. Clinical scientists now constitute a highly skilled and often underutilised group of individuals with training in areas such as clinical evaluation, 12-lead electrocardiography (ECG) interpretation, and echocardiography. These skills place them in a unique position to offer a full screening evaluation in a single consultation. The aim of this study was to implement and evaluate a novel clinical scientist-led screening clinic for first-degree relatives of patients with hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM). The clinical scientist-led screening clinic was established at a London tertiary centre to allow review of asymptomatic, first-degree relatives of patients with a confirmed diagnosis of HCM or DCM, independent of a cardiology consultant. Patients were evaluated with history, examination, ECG, and echocardiography, with further investigations if deemed necessary. A retrospective review was performed of the first 200 patients seen in the clinic.
Results
Of the 200 individuals reviewed between September 2019 and July 2022, 99 had a proband with HCM and 101 a proband with DCM. Overall, 169 individuals (85%) revealed normal screenings and were discharged. Thirty-one individuals (15.5%), all asymptomatic, revealed ECG changes and/or significant echocardiographic findings. Of these, 21 individuals (10.5% of the total cohort) were subsequently diagnosed with a cardiomyopathy or early phenotypic changes consistent with a cardiomyopathy (11 with HCM and 10 with DCM). These individuals were referred on to an inherited cardiac conditions consultant clinic for regular follow-up. Overall, 179 consultant clinic appointments were saved which could instead be allocated to patients requiring specialist consultant input.
Conclusions
This is the first description of a clinical scientist-led screening clinic for first-degree relatives of patients with HCM and DCM. The findings demonstrate that implementation of such a service into routine clinical practice is feasible, effective, safe, and can free up capacity in consultant clinics for patients requiring specialist input.
Efforts have been made over the last five decades to create effective ultrasonic contrast media (UCM) for cardiac and noncardiac applications. The initial UCM was established in the 1980s, following publications from the 1960s that detailed the discovery of ultrasonic contrast enhancement using small gaseous bubbles in echocardiographic examinations. An ideal contrast medium for echography should be nontoxic, capable of being injected intravenously, able to travel through pulmonary, cardiac, and capillary circulations, and stable for recirculation. Examples of current commercial contrast media include Definity, Optison, Sonazoid, and SonoVue, which have demonstrated potential for various clinical purposes, both on- and off-label. Several possible UCMs have been developed or are in progress. Advancements in comprehending the physical, chemical, and biological characteristics of microbubbles have significantly improved the visualization of tumor blood vessels, the identification of areas with reduced blood supply, and the enhanced detection of narrowed blood vessels. Innovative advances are expected to enhance future applications such as ultrasonic molecular imaging and therapeutic utilization of microbubbles.
Cardiovascular death is the main cause of death in patients with end-stage kidney disease (ESKD). Left ventricular hypertrophy (LVH) and left atrial diameter (LAD) enlargement are frequent cardiac alterations in patients with ESKD and are major risk factors for cardiovascular events. However, it remains unclear whether there is an association between combined LAD or LVH and all-cause or cardiovascular mortality in this population.
A single-centre, retrospective cohort study including 576 haemodialysis (HD) patients was conducted. Patients were evaluated by cardiac ultrasound, and the study cohort was divided into four groups according to LAD and LVH status: low LAD and non-LVH; low LAD and LVH; high LAD and non-LVH; and high LAD and LVH. We used Kaplan–Meier analysis and Cox proportional hazard regression to analyse all-cause and cardiovascular mortality after multivariate adjustment.
LAD was associated with an increased risk of all-cause mortality (HR 2.371, 1.602–3.509; p < 0.001). No significant differences were found between LVH and the risk of all-cause mortality. Patients with high LAD and LVH had significantly greater all-cause and cardiovascular mortality than did those with low LAD and non-LVH after adjustments for numerous potential confounders (HR 3.080, 1.608–5.899; p = 0.001) (HR 4.059, 1.753–9.397; p = 0.001).
Among maintenance haemodialysis (MHD) patients, LAD was more strongly associated with mortality than was LVH. A high LAD and LVH are associated with a greater risk of mortality. Our results emphasize that the occurrence of LAD and LVH in combination provides information that may be helpful in stratifying the risk of MHD patients.
BACKGROUND
The effect of sevoflurane on left ventricular diastolic function is not well understood. We hypothesized that parameters of diastolic function may improve under sevoflurane anesthesia in patients with preexisting diastolic dysfunction compared to patients with normal diastolic function.
METHODS
This observational study included 60 patients undergoing breast surgery or laparoscopic cholecystectomy. Patients were assigned to diastolic dysfunction (n = 34) or normal (n = 26) groups of septal e’ < 8 or ≥ 8.0 cm/s on the first thoracic echocardiography (TTE) performed before anesthesia. During anesthesia, sevoflurane was maintained at 1 to 2 minimum alveolar concentration (MAC) to maintain the bispectral index at 40 to 50. At the end of surgery, the second TTE was performed under 0.8 to 1 MAC of sevoflurane with the patient breathing spontaneously without ventilator support. Primary end point was the percentage change (Δ) of e’ on 2 TTEs (Δe’). Secondary end points were ΔE/e’, Δleft atrial volume index (ΔLAVI), and Δtricuspid regurgitation maximum velocity (ΔTR Vmax). These percentage changes (Δ) were compared between diastolic dysfunction and normal groups.
RESULTS
e’ (Δe’: 30 [6, 64] vs 0 [−18, 11]%; P < .001), mitral inflow E wave velocity (E), mitral inflow E/A ratio (E/A), and mitral E velocity deceleration time (DT) improved significantly in diastolic dysfunction group compared to normal group. LAVI decreased in diastolic dysfunction group but did not reach statistical significance between the 2 groups (ΔLAVI:−15 [−31, −3] vs −4 [−20, 10]%, P = .091). ΔE/e’ was not different between the 2 groups (11 [−16, 26] vs 12 [−9, 22]%, P = .853) (all: median [interquartile range, IQR]). TR was minimal in both groups.
CONCLUSIONS
In this study, echocardiographic parameters of diastolic function, including septal e’, E, E/A, and DT, improved with sevoflurane anesthesia in patients with preexisting diastolic dysfunction, but remained unchanged in patients with normal diastolic function.
Objective: Various cardiac arrhythmias, primarily atrial fibrillation (AF), have been reported to occur in 7% to 22% of patients hospitalized due to coronavirus disease 2019 (COVID-19). It has been shown that P wave dispersion (PWD) predicts the development of AF in different clinical situations and is closely related to the inflammatory process. The aim of this study is to determine the relationship between PWD and the development of new-onset AF in hospitalized patients due to COVID-19. Methods: 51 COVID-19 patients who developed AF and 72 COVID-19 patients who did not develop AF were included in the study as the control group retrospectively. Electrocardiography (ECG) was performed in all patients and PWD was calculated. In addition, demographic data, imaging findings and laboratory test results of all COVID-19 patients were obtained from the institutional digital database and recorded. Results: Patients who developed AF were older and had a higher frequency of hypertension and heart failure (p
There have been numerous attempts over the past 50 years to develop efficient ultrasound contrast media (UCM) for both cardiac and noncardiac uses. In other words, the first UCM was created in the 1980s as a result of early reports from the 1960s documenting the findings of ultrasound contrast enhancement by microscopic gaseous bubbles during echocardiographic tests. A nontoxic UCM (Definity, Optison, Sonazoid, and SonoVue are some of the current commercial contrast media for echography that have shown promise in a range of on- and off-label clinical purposes) that may be injected intravenously, travels through the pulmonary, cardiac, and capillary circulations, and is stable for recirculation would be ideal. Many potential UCMs have been developed or are currently being worked on. The understanding of the physical, chemical, and biological behavior of microbubbles has greatly advanced in increase tumor vascularity, highlight sites of ischemia, and improve the ability to see vascular stenosis. Future potential, like ultrasonic molecular imaging and therapeutic uses of microbubbles, are anticipated to benefit from new inventive advancements.
POCUS is a real game-changer for the diagnosis of acute heart failure (AHF). It is readily available at the bedside and provides crucial information for the management of patients. The cardiac evaluation, performed with the FoCUS approach (focus cardiac ultrasound) offers an immediate assessment of cardiac morphology and function, pericardial effusion and gross valvular abnormalities, which may rapidly indicate the main cause for decompensation. Lung ultrasound can be easily integrated to FoCUS to assess pulmonary congestion by sonographic B-lines and pleural effusion, thus suggesting the degree of decompensation. The portability of this tool, whose information can be readily used at the bedside, with minimal discomfort or risk for the patient, without using of contrast material or ionizing radiation, can significantly speed up the correct diagnosis and the decision-making process, making integrated cardiopulmonary POCUS the most versatile and cost-effective imaging approach for the evaluation of patients with acute cardiovascular conditions.
Background
It has not yet been conclusively determined whether reduced left ventricular global longitudinal strain (LV GLS) after COVID-19 contributes to a reduction in exercise capacity. Our own studies showed a possible mild myocardial involvement in the form of reduced LV GLS in athletes after COVID-19 compared with healthy athletes. The aims of this prospective follow-up study were to investigate the development of LV GLS over a 3-month period in athletes after COVID-19 and the possible relationship between LV GLS and physical performance.
Methods
LV GLS was determined in four-, two-, and three-chamber views and assessed offline by a blinded investigator in 96 recreational athletes (mean age 33.15 ± 12.40 years, 53 male, peak VO 2 38.82 ± 11.14 ml/min/kg) at a median of two ( t 0 ) and five months ( t 1 ) after COVID-19. Cardiopulmonary exercise testing (CPET) was performed on a bicycle ergometer on both examination dates.
Results
LV GLS improved significantly between t 0 and t 1 ( t 0 −18.82 ± 2.02 vs. t 1 −19.46 ± 2.05, p < 0.001). Echocardiographic and spiroergometric parameters were within the normal clinical reference range. Maximum power increased significantly from t 0 to t 1 ( t 0 283.17 ± 83.20 vs. t 1 286.24 ± 85.22 Watt, p = 0.009) and there was a trend toward increased peak oxygen uptake ( t 0 36.82 ± 11.14 vs. t 1 38.68 ± 10.26 ml/min/kg, p = 0.069). We found no correlation between LV GLS and performance parameters, except for the respiratory exchange ratio (RER) [ ρ −0.316, (−0.501; −0.102), p < 0.050].
Conclusions
Significant improvement in LV GLS approximately five months after COVID-19 may be due to mild myocardial involvement during or shortly after COVID-19, which seems to recover. There was no correlation between LV GLS and performance parameters, except for an inverse correlation of LV GLS and RER, suggesting insufficient exercise intolerance at lower GLS values. Further studies on the development of GLS in athletes or in the general population with moderate and severe disease courses would be informative as well as the comparison of pre-COVID-19 with post-COVID-19 echocardiography to evaluate the effects of COVID-19 on cardiac function.
The goal of this study was to assess whether subtle changes in myocardial work indices may predict left ventricular (LV) remodeling and major cardiac events (MACEs) in patients with a first ST-elevation acute myocardial infarction (STEMI) and preserved LVEF after successful myocardial revascularization with PCI. Methods. Consecutive STEMI patients in sinus rhythm and with an LV ejection fraction ≥ 50% following a successful PCI were recruited. Conventional and two-dimensional speckle tracking echocardiography (2D-STE) was conducted within 36 h of the PCI and 3 months later. Patients having an increase of more than 20% in LV diastolic volume were included in the LV remodeling group. MACEs were noted throughout a four-year period of follow-up. Results: The study comprised 246 STEMI patients with a mean age of 66; 72% of whom were men. In 24% (58) of the patients, LV remodeling developed. These patients were older, more frequently hypertensive, and had a smoking history. They also exhibited significantly lower baseline and 3-month values for the myocardial global index (GWI), global constructive work (GCW), and global myocardial efficiency (GWE). The cut-off values of 1670 mmHg% for GWI and 83% for GWE were predictive of LV remodeling (p < 0.0001). During the four-year follow-up period, 19% of STEMI patients experienced a MACE, involving 15% from non-LV remodelers and 34% from LV remodelers (p = 0.01). The cut-off values for baseline GWI of 1680 mmHg% and baseline GWE of 84% had the best accuracy in predicting MACEs. In conclusion, non-invasive myocardial work indices offered a reproducible and accurate method to predict post-MI LV remodeling and MACEs.
Background:
Using easy-to-determine bedside measurements, we developed an echocardiographic algorithm for predicting left ventricular ejection fraction (LVEF) and longitudinal strain (LVLS) in patients with septic shock.
Methods:
We measured septal and lateral mitral annular plane systolic excursion (MAPSE), septal and lateral mitral S-wave velocity, and the left ventricular longitudinal wall fractional shortening in patients with septic shock. We used a conditional inference tree method to build a stratification algorithm. The left ventricular systolic dysfunction was defined as an LVEF <50%, an LVLS greater than -17%, or both.
Results:
We included 71 patients (males: 61%; mean [standard deviation] age: 61 [15] yr). Septal MAPSE (cut-off: 1.2 cm) was the best predictor of left ventricular systolic dysfunction. The level of agreement between the septal MAPSE and the left ventricular systolic dysfunction was 0.525 [0.299-0.751]. A septal MAPSE ≥1.2 cm predicted normal LVEF in 17/18 patients, or 94%. In contrast, a septal MAPSE <1.2 cm predicted left ventricular systolic dysfunction with impaired LVLS in 46/53 patients (87%), although 32/53 (60%) patients had a preserved LVEF.
Conclusions:
Septal MAPSE is easily measured at the bedside and might help clinicians to detect left ventricular systolic dysfunction early-especially when myocardial strain measurements are not feasible.
Aims
Dynamic left ventricular (LV) outflow tract obstruction (LVOTO) is associated with symptoms and increased risk of developing heart failure in hypertrophic cardiomyopathy (HCM). The association of LVOTO and LV twist mechanics has not been well studied in HCM. The aim of the study was to compare the pattern of LV twist in patients with HCM associated with asymmetrical septal hypertrophy with and without LVOTO.
Methods and results
Echocardiography (including speckle tracking) was performed in 212 patients with HCM, divided according to the absence (n = 130) or presence (n = 82) of LVOTO (defined as peak pressure gradient ≥30 mmHg either at rest and/or with Valsalva manoeuvre). Patients with LVOTO were older, had smaller LV dimensions, a higher LV ejection fraction (LVEF), a longer anterior mitral valve leaflet length, and a higher early transmitral pulsed wave to septal tissue Doppler velocity ratio (E/E′). A univariate analysis showed that peak twist was significantly higher in patients with LVOTO compared with patients without LVOTO (19.7 ± 7.3 vs. 15.7 ± 6.0, P = 0.00015). Peak twist was similarly enhanced in patients with LVOTO, manifesting only during Valsalva (19.2 ± 5.6, P = 0.007) and patients with resting LVOTO (19.9 ± 8.0, P = 0.00004) compared with patients without LVOTO (15.7 ± 6.0). A stepwise forward logistic regression analysis showed that LVEF, LV end-systolic dimension indexed to body surface area, anterior mitral valve leaflet length, E/E′, and peak twist were all independently associated with LVOTO.
Conclusion
This study demonstrates that increased peak LV twist is independently associated with LVOTO in patients with HCM. Peak twist was similarly exaggerated in patients with only latent LVOTO, suggesting that it may play a contributory role to LVOTO in HCM.
Subject:
Rheumatoid arthritis patients are at risk of developing cardiovascular disease such as right heart failure and pulmonary hypertension (PH). Arterial stiffness can be used to assess pulmonary hemodynamics. Noninvasive approaches can also be used to assess pulmonary hemodynamics. Recently, there have been reports that pulmonary pulse transit time (PPTT) may also be a useful measure. This study aims to examine the effects of pulmonary hemodynamic alterations on PPTT in RA patients.
Methods:
Forty RA patients and 40 healthy controls were included in the study. Sociodemographic characteristics, laboratory data, and echocardiographic examinations were performed in both groups. Conventional echocardiographic examination included left and right ventricular systolic and diastolic diameters, right ventricular myocardial performance index (RVMPI), right ventricular diastolic function, estimated pulmonary artery systolic pressure (sPAP), tricuspid annular plane systolic excursion (TAPSE), pulmonary artery stiffness (PAS), and PPTT. Right ventricular diastolic and systolic volumes, right ventricular ejection fraction (RVEF), and right ventricular fractional area change (RVFAC) were determined by four-dimensional echocardiography (4DE).
Results:
There was no difference between the sPAP values of the patients. RVMPI and PAS were increased in RA patients compared with controls. The PPTT was shortened in RA patients and correlated with RVEF, RVFAC, RVMPI, TAPSE/sPAP, disease duration, and C-reactive protein (CRP). In univariate linear regression analysis, PPTT (p < .001) was thought to be an independent predictor of PAS. RVFAC, disease duration, and PAS were also independent predictors of PPTT.
Conclusion:
In RA patients, PPTT may be the first evidence of early abnormalities in pulmonary vascular hemodynamics. PPTT and PAS are the values that may predict each other in RA patients. Due to its more practical application, PPTT can be used instead of PAS to assess pulmonary hemodynamics.
Background:
Left atrial (LA) function is a very important prognostic indicator for many cardiovascular diseases. In this study, we aimed to determine whether LA function is impaired in children with Kawasaki disease (KD) and to analyze the relationships between LA deformation and conventional echocardiographic parameters and laboratory markers.
Methods:
A total of 50 KD patients during different disease phases and 50 age- and sex-matched controls were retrospectively analyzed. Patients in the acute phase based on coronary artery dilation (CAD) were subdivided into Group I (with CAD) and Group II (without CAD) and compared.
Results:
During the acute phase, KD patients had a lower peak LA longitudinal strain (PLALS), a lower LA strain peak during LA contraction (LASct), and a lower LA strain rate peak during LA contraction (LASRct) than the controls. The PLALS, LASct and LASRct began to increase during the subacute phase, and during the convalescent phase, all LA strains in patients had recovered to normal compared with the control subjects. Subgroup analysis revealed that, compared with Group II, Group I had higher C-reactive protein (CRP) and serum N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels; however, there were no significant differences in LA strains. Only the PLALS during the acute phase was negatively correlated with left ventricular mass index, CRP and NT-proBNP.
Conclusions:
In patients with KD, LA function is impaired during the acute phase, and this impairment is transient. Two-dimensional speckled tracking echocardiography is a useful tool for detecting subclinical LA dysfunction.
Echocardiography is the most widely accepted diagnostic tool for assessment of cardiac function and morphology in dogs and is usually performed in lateral recumbency. However, in some situations or in stressed patients, it is necessary to perform it in a standing position. Only one study evaluated the effects of animal position on selected two-dimensional and M-mode echocardiographic variables in four healthy dogs of different breeds, but not in brachycephalic breeds. In these breeds echocardiographic evaluation is sometimes needed in standing position due to the severity of brachycephalic obstructive airway syndrome and the impossibility of managing them in lateral recumbency without causing stress and choking danger. The objectives of this prospective, observational study were to (a) evaluate the effects of lateral recumbency versus standing positions on echocardiographic M-mode, two-dimensional, Doppler flow measurements, and Tissue Doppler imaging in healthy French bulldogs (FBs); (b) assess the intra- and interoperator variability of the standing echocardiographic examination; and (c) compare the obtained results with the available data from the literature. Forty healthy FBs (20 females/20 males) were sampled. The median age and weight were 2.45 years (IQR25-75 , 1.18-4.16) and 12.7 kg (IQR25-75 , 10.88-13.46). There were no differences between lateral recumbency and standing position measurements (P > 0.05). Intraoperator coefficients of variation (CVs) ranged from 0.5% to 10.1%, whereas interoperator CVs ranged from 1% to 14.2%. Only E wave peak velocity, aortic, and pulmonary flows were consistent with the previously published reference ranges in lateral recumbency. In conclusion, echocardiography in a standing position could be a useful tool in FBs.
Objective:
Microbubble contrast echocardiography with a late positive signal enables the detection of intrapulmonary vascular dilation, including hepatopulmonary syndrome, in patients with end-stage liver disease. We assessed the relationship between the severity of bubble study and clinical outcome.
Methods:
We retrospectively analyzed 163 consecutive patients with liver cirrhosis who underwent an echocardiogram with bubble study from 2018 to 2021. Patients who were diagnosed with a late positive signal were divided into three groups: grade 1 (1-9 bubbles), grade 2 (10-30 bubbles) and grade 3 (>30 bubbles).
Results:
Fifty-six percent of the patients had a late positive bubble study (grade 1: 31%, grade 2: 23%, grade 3: 46%). Patients with grade 3 had a significantly higher international normalized ratio, model for end-stage liver disease score and Child-Pugh score and a lower peripheral oxygen saturation compared with patients with a negative study. In patients undergoing liver transplant (LT), survival rates were similar among the groups (3-mo: >87%, 1-y: >87%, 2-y: >83%). However, survival rate was lower in grade 3 patients without LT (3-mo: 81%, 1-y: 64%, 2-y: 39%).
Conclusion:
Patients with grade 3 had much worse mortality without LT compared with other groups. However, after LT, all grades had equal survival. Therefore, patients with grade 3 may be considered as higher priority for LT.
Background:
A positive family history of hypertension (FHH) (+FHH) is associated with elevated left ventricular mass (LVM). Regular physical activity (PA) may eliminate differences in LVM between +FHH and negative family history of hypertension (-FHH) adults. The aim of this study was to determine if a +FHH is associated with a greater LVM compared to a -FHH group within a sample of young, mostly active healthy adults with and without statistically controlling for PA.
Methods:
Healthy young (18-32 y) participants self-reported FHH status and habitual moderate and vigorous PA frequency. Participants then underwent an echocardiogram.
Results:
Of the 61 participants, 32 (M=11, W=21; non-active=8) reported -FHH and the remaining 29 (M=13, W=16; non-active=2) reported a +FHH. Mann-Whitney tests found the +FHH group had greater LVM (-FHH 129.5±41.8, +FHH 155.2±42.6 g, P=0.015) and LVM/body surface area (BSA) (-FHH 73.5±17.4, +FHH 88.4±17.3 g/m2, P=0.004). Separate ANCOVA models accounting for moderate and vigorous PA found that FHH status independently predicted LVM/BSA and PA frequencies were significant modifiers (ANCOVA controlling moderate PA: FHH status P=0.004, partial η2=0.133; moderate PA P=0.020, partial η2=0.089), (ANCOVA controlling vigorous PA: FHH status P=0.004, partial η2=0.132; vigorous PA P=0.007, partial η2=0.117).
Conclusions:
This analysis suggests that physically active young adults with a +FHH have elevated LVM compared to their -FHH counterparts. This finding is independent of their habitual moderate and vigorous physical activity frequencies.
In an effort to determine what clinically useful information regarding left ventricular diastolic function can be inferred noninvasively with pulsed wave Doppler echocardiography, mitral flow velocity patterns and measured variables were correlated with hemodynamic findings in 70 patients: 30 with coronary artery disease, 20 with idiopathic congestive cardiomyopathy, 14 with a restrictive myocardial process and 6 without significant cardiac disease. The effect of sudden changes in hemodynamics on the mitral flow velocity pattern was also investigated in a subgroup of patients who had simultaneous recording of mitral flow velocity and left ventricular pressure before and after left ventriculography. Mitral flow velocity recordings from 30 healthy adults served as a reference group.This analysis suggests that 1) the majority of patients with these cardiac disorders demonstrate abnormal mitral flow velocity patterns or variables; 2) markedly different flow velocity patterns can be seen in patients with impaired left ventricular relaxation; 3) the different mitral patterns appear to relate more to myocardial function and hemodynamic status than to the type of disease process present; 4) certain mitral patterns suggest different filling pressures and rates of early diastolic left ventricular filling; 5) an increase in left atrial pressure can “normalize” an abnormal mitral flow velocity pattern and “mask” a left ventricular relaxation abnormality; and 6) the different patterns appear to represent a dynamic continuum with the potential to change from one to another as a result of disease progression, medical therapy or sudden changes in hemodynamics.It is concluded that, despite the indirect method of estimation and certain limitations, mitral flow velocity recordings have clinical potential in assessing left ventricular diastolic function that merits further investigation.
A noninvasive method is described for measuring the pressure drop across the mitral valve in mitral stensois by Doppler ultrasound. A maximum frequency estimator was used to record maximum velocity in the Doppler signal from the mitral jet. Provided the angle between the ultrasound beam and the maximum velocity is close to zero the pressure drop can be calculated directly. Good correlation was found between Doppler measurements and simultaneous pressure recordings during heart catheterisation in 10 patients. No false negative or false positive diagnoses of mitral stenosis were made among 55 patients (35 patients with mitral stenosis and 20 patients with other valve lesions). The measurements were easy to perform in most patients and the method seems well suited both to diagnose and to follow patients with mitral stenosis.
The color Doppler echocardiographic studies and aortic angiograms of all patients who had these procedures performed within 2 weeks of each other between October 1984 and August 1985 were reviewed to determine whether any parameters of the regurgitant jet visualized by color Doppler study predicted the severity of aortic insufficiency as assessed by angiographic grading. Patients with an aortic valve prosthesis were excluded. Twenty-nine patients had aortic insufficiency and had adequate color Doppler studies for analysis. The mean time between color Doppler examination and angiography was 2.3 days (range 0 to 12).The maximal length and area of the regurgitant jet were poorly predictive of the angiographic grade of aortic insufficiency. The short-axis area of the regurgitant jet from the parasternal short-axis view at the level of the high left ventricular outflow tract relative to the short-axis area of the left ventricular outflow tract at the same location best predicted angiographic grade, correctly classifying 23 of 24 patients. However, the jet could be seen from this view in only 24 of the 29 patients. The height of the regurgitant jet relative to left ventricular outflow tract height measured from the parasternal long-axis view just beneath the aortic valve correctly classified 23 of the 29 patients. Mitral stenosis or valve prosthesis, which was present in 10 patients, did not interfere with the diagnosis or quantitation of aortic insufficiency by these methods.The thickness of the regurgitant stream at its origin relative to the size of the left ventricular outflow tract is a better predictor of the severity of aortic insufficiency as judged by angiographic grading than is the area of the regurgitant jet or the depth to which the jet extends in the left ventricle.
It remains uncertain whether prosthetic ring size should be used interchangeably withmeasured left ventricular outflow tract (LVOT) diameter in the continuity equation to estimate the aortic prosthetic valve area by transthoracic Doppler echocardiography. To determine the difference in area caused by this substitution, the area of the prosthetic valve was calculated in 143 patients with aortic bioprostheses by use of the standard continuity equation with the measured LVOT diameter (LVOT method) and then with the bioprosthetic size (size method). Compared with known in vitro prosthetic valve areas, the LVOT method (r=0.86; standard error of the estimate ± 0.16 cm2; p<0.001) was more accurate than the size method (r=0.74; standard error of the estimate ±0.40 cm2; p<0.001). The prosthetic valve area estimated by the size method overestimated the area estimated by the LVOT method by an average of 15%±23% (p<0.001). This difference in area between the two methods has increased with the interval since implantation of the bioprosthesis (p=0.01). It is concluded that prosthetic size should not be used instead of LVOT diameter during calculation of aortic prosthetic valve area. This restriction is particularly important in patients with older bioprostheses.
Objectives:
This study was conducted to assess the diagnostic role of Doppler echocardiography in constrictive pericarditis.
Background:
It has been observed that patients with constrictive pericarditis have a characteristic Doppler pattern of respiratory variation in ventricular filling and central venous flow velocities. However, the observation was based on a small number of patients with known diagnosis.
Methods:
We reviewed the echocardiographic features of 28 patients (21 men and 7 women; mean age +/- SD 55 +/- 15 years) with suspected constrictive pericarditis who underwent exploratory thoracotomy or pericardiectomy.
Results:
At operation, constrictive pericarditis was diagnosed in 25 patients, restriction in 1 and normal pericardium in 2. Of the 25 patients with constriction, correct preoperative Doppler diagnosis was made in 22 (88%) and Doppler echocardiography showed restriction in 3. In two patients with a normal pericardium, Doppler features were consistent with constriction in one patient and were normal in the other. In the one patient with restriction, Doppler echocardiography showed restriction. In 19 patients with surgically proved constriction, repeat Doppler study after pericardiectomy showed normal findings in 14 and restriction in 5. Twelve of the 14 patients with normalized Doppler findings became asymptomatic, whereas all 5 with restrictive Doppler features remained symptomatic.
Conclusions:
Doppler echocardiography performed simultaneously with respiratory recording is highly sensitive for diagnosing constrictive pericarditis, and it appears to predict functional response to pericardiectomy.
Objectives:
The goal of this study was to develop an accurate, simplified proximal isovelocity surface area (PISA) method for calculating volume flow rate using lower blue-red interface velocity produced by a color Doppler zero baseline shift technique.
Background:
The Doppler color proximal isovelocity surface area method has been shown to be accurate for calculating the volume flow rate (Q) across a narrowed orifice by the formula Q = PISA x Blue-red interface velocity. A hemispheric model is generally used to calculate proximal isovelocity surface area (PISA = 2 pi a2, where a = the radius corresponding to the blue-red interface velocity). Although a hemispheric model is simple, requiring measurement of one radius, it may underestimate the actual volume flow rate because, in the general case, the shape of a proximal isovelocity surface area is hemielliptic. Although a hemielliptic model is generally more accurate for calculating proximal isovelocity surface area, it is more complex, requiring measurement of two orthogonal radii.
Methods:
Sixteen in vitro constant flow model studies were performed using planar circular orifices (diameter range 6 to 16 mm). The blue-red interface velocity was changed from 3 to 54 cm/s using color Doppler zero baseline shift.
Results:
1) With decreasing blue-red interface velocity, the size of the proximal isovelocity surface area was increased, and its shape changed from hemielliptic to hemispheric. 2) With the blue-red interface velocity in the range 11 to 15 cm/s, the proximal isovelocity surface area became nearly hemispheric; however, it was difficult to determine the blue-red interface radius at a blue-red interface velocity < 10 cm/s because of interface fluctuations. 3) Calculated volume flow rate using the hemispheric proximal isovelocity surface area model with a single radius was relatively accurate at a blue-red interface velocity of 11 to 15 cm/s (mean percent difference from actual volume flow rate was -3.6%).
Conclusions:
Because the shape of the proximal isovelocity surface area is nearly hemispheric at a blue-red interface velocity of 11 to 15 cm/s, volume flow rate can be accurately calculated in this proximal isovelocity surface area interface velocity range (produced by zero baseline shift) by measuring a single-interface radius. This approach should be clinically useful for calculating the volume flow rate across stenotic and regurgitant valves and across shunt defects.
Objectives. The purpose of this study was to determine whether left atrial size and ejection fraction are related to left ventricular filling pressures in patients with coronary artery disease.Background. In patients with coronary artery disease, left ventricular filling pressures can be estimated by using Doppler mitral and pulmonary venous flow velocity variables. However, because these flow velocities are age dependent, additional variables that indicate elevated left ventricular filling pressures are needed to increase diagnostic accuracy.Methods. Echocardiographic left atrial and Doppler mitral and pulmonary venous flow velocity variables were correlated with left ventricular filling pressures in 70 patients undergoing cardiac catheterization.Results. Left atrial sin and volumes were larger and left atrial ejection fractions were lower in patients with elevated left ventricular filling pressures. Mean pulmonary wedge pressure was related to mitral E/A wave velocity ratio (r = 0.72), left atrial minimal volume (r = 0.70), left atrial ejection fraction (r = −0.66) and atrial filling fraction (r = −0.66). Left ventricular end-diastolic and A wave pressures were related to the difierence in pulmonary venous and mitral A wave duration (both r = 0.77). By stepwise multilinear regression analysis, the ratio of mitral E to A wave velocity was the most important determinant of pulmonary wedge (r = 0.63) and left ventricular pre-A wave (r = 0.75) pressures, whereas the difference in pulmonary venous and mitral A wave duration was the most important variable for both left ventricular A wave (r = 0.75) and left ventricular end-diastolic (r = 0.80) pressures. The sensitivity of a left atrial minimal volume >40 cm3 for identifying a mean pulmonary wedge pressure >12 mm Hg was 82%, with a specificity of 98%.Conclusions. Left atrial size, left atrial ejection fraction and the difference between mitral and pulmonary venous flow duration at atrial contraction are independent determinants of left ventricular filling pressures in patients with coronary artery disease. The additive value of left atrial size and Doppler variables in estimating filling pressures and the possibility that left atrial size may be less age dependent than other mitral and pulmonary venous flow velocity variables merit further investigation.
Objectives:
This study assessed the clinical utility of mitral annulus velocity in the evaluation of left ventricular diastolic function.
Background:
Mitral inflow velocity recorded by Doppler echocardiography has been widely used to evaluate left ventricular diastolic function but is affected by other factors. The mitral annulus velocity profile during diastole may provide additional information about left ventricular diastolic function.
Methods:
Mitral annulus velocity during diastole was measured by Doppler tissue imaging (DTI) 1) in 59 normal volunteers (group 1); 2) in 20 patients with a relaxation abnormality as assessed by Doppler mitral inflow variables (group 2) at baseline and after saline loading; 3) in 11 patients (group 3) with normal diastolic function before and after intravenous nitroglycerin infusion; and 4) in 38 consecutive patients (group 4) undergoing cardiac catheterization in whom mitral inflow velocity and tau as well as mitral annulus velocity were measured simultaneously.
Results:
In group 1, mean +/- SD peak early and late diastolic mitral annulus velocity was 10.0 +/- 1.3 and 9.5 +/- 1.5 cm/s, respectively. In group 2, mitral inflow velocity profile changed toward the pseudonormalization pattern with saline loading (deceleration time 311 +/- 84 ms before to 216 +/- 40 ms after intervention, p < 0.001), whereas peak early diastolic mitral annulus velocity did not change significantly (5.3 +/- 1.2 cm/s to 5.7 +/- 1.4 cm/s, p = NS). In group 3, despite a significant change in mitral inflow velocity profile after nitroglycerin, peak early diastolic mitral annulus velocity did not change significantly (9.5 +/- 2.2 cm/s to 9.2 +/- 1.7 cm/s, p = NS). In group 4, peak early diastolic mitral annulus velocity (r = -0.56, p < 0.01) and the early/late ratio (r = -0.46, p < 0.01) correlated with tau. When the combination of normal mitral inflow variables with prolonged tau (> or = 50 ms) was classified as pseudonormalization, peak early diastolic mitral annulus velocity < 8.5 cm/s and the early/late ratio < 1 could identify the pseudonormalization with a sensitivity of 88% and specificity of 67%.
Conclusions:
Mitral annulus velocity determined by DTI is a relatively preload-independent variable in evaluating diastolic function.
The mean pressure drop across the mitral valve and atrioventricular pressure half-time were measured noninvasively by Doppler ultrasound in 40 normal subjects, in 17 patients with mitral regurgitation, 32 patients with mitral stenosis and 12 with combined stenosis and regurgitation. In normal subjects pressure half-times were 20--60 msec, in patients with isolated mitral regurgitation 35--80 msec and in patients with mitral stenosis 90--383 msec. There was no significant change in pressure half-time with exercise or on repeat examinations, indicating relative independence of mitral flow. In 25 patients with mitral stenosis and seven with combined stenosis and regurgitation, pressure half-time was related to mitral valve area calculated from catheterization data. Increasing pressure half-times occurred with decreasing mitral valve area, and this relationship was not influenced by additional mitral regurgitation. Noninvasive measurement of pressure half-time together with mean pressure drop was useful for evaluating patients with mitral valve disease.
To evaluate the normal range of Doppler-derived velocities and gradients, their relation to direct flow measurements and the importance of prosthetic valve design on the relation between Doppler and catheter-derived gradients, five sizes of normal St. Jude bileaflet, Medtronic-Hall tilting disc, Starr-Edwards caged ball and Hancock bioprosthetic aortic valves were studied with use of a pulsatile flow model. A strong linear correlation between peak velocity and peak flow, and mean velocity and mean flow, was found in all four valve types (r = 0.96 to 0.99). In small St. Jude and Hancock valves, Doppler velocities and corresponding gradients increased dramatically with increasing flow, resulting in velocities and gradients as high as 4.7 m/s and 89 mm Hg, respectively. The ratio of velocity across the valve to velocity in front of the valve (velocity ratio) was independent of flow in all St. Jude, Medtronic-Hall, Starr-Edwards and Hancock valves when the two lowest flow rates were excluded for Hancock valves. Although Doppler peak and mean gradients correlated well with catheter peak and mean gradients in all four valve types, the actual agreement between the two techniques was acceptable only in Hancock and Medtronic-Hall valves. For St. Jude and Starr-Edwards valves, Doppler gradients significantly and consistently exceeded catheter gradients with differences as great as 44 mm Hg. Thus, Doppler velocities and gradients across normal prosthetic heart valves are highly flow dependent. However, the velocity ratio is independent of flow.(ABSTRACT TRUNCATED AT 250 WORDS)
In patients with heart disease, changes in left ventricular filling pressures produce alterations in the Doppler transmitral flow velocity and isovolumetric relaxation time. This investigation explored the hypothesis that combining isovolumetric relaxation time with measurements derived from the transmitral flow velocity can be used to estimate left ventricular end-diastolic pressure. Simultaneous Doppler and left ventricular pressure recordings were obtained in 33 patients (24 men with a mean age of 58 +/- 11 years) and an ejection fraction ranging from 15% to 74% (mean 55 +/- 15%). The following Doppler measurements correlated significantly with left ventricular end-diastolic pressure (range 4 to 36 mm Hg): isovolumetric relaxation time (IVRT; r = -0.73), atrial filling fraction (AFF; r = -0.66), deceleration time (DT; r = -0.59), ratio of early transmitral flow velocity to atrial flow velocity (E/A ratio; r = -0.53) and time from termination of mitral flow to the electrocardiographic R wave (MAR; r = 0.37). Combining these measurements into a multilinear regression equation provided a more accurate estimate of end-diastolic pressure (LVEDP; r = 0.80; SEE = 7.4). The equation LVEDP = 46 -0.22 IVRT -0.10 AFF -0.03 DT -(2 divided by E/A) + 0.05 MAR was tested prospectively in 26 additional patients (mean age 55 +/- 11 years; ejection fraction 41 +/- 23%) with simultaneous Doppler and hemodynamic recordings but with the two measurements made independently, in blinded fashion, by additional observers. Estimated and measured end-diastolic pressures correlated well with each other (r = 0.86).(ABSTRACT TRUNCATED AT 250 WORDS)
This study was designed to evaluate the relation between the velocity of flow propagation and left ventricular relaxation by using color M-mode Doppler echocardiography to analyze flow propagation in the left ventricle.
Noninvasive attempts to identify alterations in left ventricular relaxation have been hampered because both the relaxation rate and left atrial filling pressure are the determinants of peak early velocity and filling rate.
Color M-mode velocity data were transferred to a microcomputer and compared with conventional pulsed Doppler data to assess the ability of color M-mode echocardiography to analyze velocity field properties. The velocity of flow propagation was measured as the slope of the flow wave front during early filling in normal subjects (n = 29) and in patients with disease that alters relaxation (dilated cardiomyopathy [n = 31], ischemic cardiomyopathy [n = 8], hypertrophic cardiomyopathy [n = 5], systemic hypertension [n = 22] and aortic valve disease [n = 25]). In nine patients with end-stage dilated cardiomyopathy, echocardiographic and left heart catheterization data were obtained at baseline and during intracoronary dobutamine infusion.
Color M-mode and pulsed Doppler echocardiographic data were highly correlated (n = 217, r = 0.94, p less than 0.0001, velocity range 0.2 to 1.5 m/s). The velocity of flow propagation was lower in patients than in normal subjects (0.46 +/- 0.15 vs. 0.84 +/- 0.11 m/s, p less than 0.0001). The decrease was significant in all disease forms with or without left ventricular dilation. The velocity of flow propagation was related to peak early velocity in normal subjects (p less than 0.001) but not in patients. It varied inversely with the isovolumetric relaxation time constant during dobutamine infusion and the two variables were highly correlated (p less than 0.0001).
The velocity of flow propagation during early filling seems to be highly dependent on the left ventricular relaxation rate and could be an important tool in studying diastolic function.
In clinical color Doppler examinations, mitral regurgitant jets are often observed to impinge on the left atrial wall immediately beyond the mitral valve. In accordance with fluid dynamics theory, we hypothesized that a jet impinging on a wall would lose momentum more rapidly, undergo spatial distortion, and thus have a different observed jet area from that of a free jet with an identical flow rate.
To test this hypothesis in vivo, we studied 44 patients with mitral regurgitation--30 with centrally directed free jets and 14 with eccentrically directed impinging wall jets. Maximal color jet areas (cm2) (with and without correction for left atrial size) were correlated with mitral regurgitant volumes, flow rates, and fractions derived from pulsed Doppler mitral and aortic forward flows. The groups were compared by analysis of covariance. Mean +/- SD mitral regurgitant fraction, regurgitant volume, and mean flow rate averaged 37 +/- 17%, 3.06 +/- 2.65 l/min, and 147 +/- 118 ml/sec, respectively. The maximal jet area from color Doppler imaging correlated relatively well with the mitral regurgitant fraction in the patients with free mitral regurgitant jets (r = 0.74, p less than 0.0001) but poorly in the patients with impinging wall jets (r = 0.42, p = NS). Although the mitral regurgitant fraction was larger (p less than 0.05) in patients with wall jets (44 +/- 20%) than in those with free jets (33 +/- 15%), the maximal jet area was significantly smaller (4.78 +/- 2.87 cm2 for wall jets versus 9.17 +/- 6.45 cm2 for free jets, p less than 0.01). For the same regurgitant fraction, wall jets were only approximately 40% of the size of a corresponding free jet, a difference confirmed by analysis of covariance (p less than 0.0001).
Patients with mitral regurgitation frequently have jets that impinge on the left atrial wall close to the mitral valve. Such impinging wall jets are less predictable and usually have much smaller color Doppler areas in conventional echocardiographic views than do free jets of similar regurgitant severity. Jet morphology should be considered in the semiquantitative interpretation of mitral regurgitation by Doppler color flow mapping. Future studies of the three-dimensional morphology of wall jets may aid in their assessment.
Echocardiography and Doppler ultrasound are useful in evaluating a variety of pathological conditions affecting the pericardium. Cardiac tamponade results in right atrial collapse and right ventricular diastolic collapse detectable by echocardiography. These echocardiographic signs have a high degree of sensitivity and specificity. False-negative echocardiographic studies may be seen in patients with pulmonary hypertension, and false-positive studies for cardiac tamponade may occur in severe hypovolemia. Although cardiac tamponade is usually caused by pericardial effusion, less commonly intrapericardial clot may result in hemodynamic compromise. Pericardial clot may be echogenic, and hence the diagnosis potentially can be missed. If the intrapericardial clot is localized, the classic echocardiographic signs of pericardial effusion may be absent, and a localized mass may be seen on the echocardiogram. Increased respiratory variation in transvalvular blood flow velocities detectable by Doppler ultrasound is found in cardiac tamponade. Doppler ultrasound studies may be particularly useful in those patients in whom the characteristic echocardiographic abnormalities are absent. Both M-mode and two-dimensional echocardiography may be useful in diagnosing pericardial thickening. Constrictive pericarditis results in a variety of echocardiographic abnormalities including pericardial thickening; biatrial enlargement with good left ventricular function; a diastolic septal bounce; and a dilated inferior vena cava without significant respiratory variation. Doppler echocardiographic abnormalities are commonly found in constrictive pericarditis. Echocardiography is also useful as a guide to performing pericardiocentesis and in the detection of pericardial adhesions and pericardial metastases.
The magnitude and spatial distribution of normal leakage through mechanical prosthetic valves were studied in an in vitro model of mitral regurgitation. The effective regurgitant orifice was calculated from regurgitant rate at different transvalvular pressure differences and flow velocities. This effective orifice area was 0.6 to 2 mm2 for three tilting disc prostheses (Medtronic-Hall sizes 21, 25 and 29) and 0.2 to 1.1 mm2 for three bileaflet valves (St. Jude Medical sizes 21, 25 and 33). In the single disc valves, Doppler color flow examination disclosed a prominent central regurgitant jet around the central hole for the strut, accompanied by minor leakage along the rim of the disc (central to peripheral jet area ratio 3.3 +/- 1.2). The bileaflet prostheses showed a peculiar complex pattern: in planes parallel to the two disc axes, convergent peripherally arising jets were visualized, whereas in orthogonal planes several diverging jets were seen. Mounting the disc and bileaflet valves on a water-filled tube allowed reproduction and interpretation of this pattern: for the bileaflet valve, the jets originated predominantly from valve ring protrusions that contained the axis hinge points and created a converging V pattern in planes parallel to the leaflets and a diverging V pattern in orthogonal planes. Similar patterns were observed during transesophageal echocardiography in 20 patients with a normally functioning St. Jude prosthesis. In 10 patients with a Medtronic-Hall valve, a dominant central jet was observed with one or more smaller peripheral jets. The median central to peripheral jet area ratio was 5 to 1.(ABSTRACT TRUNCATED AT 250 WORDS)
To test whether the continuity equation can be applied to the noninvasive assessment of prosthetic aortic valve function, Doppler echocardiography was performed in 67 patients (mean age, 58 +/- 14 years) within 10 +/- 6 days after valve replacement with St. Jude Medical valves. All patients were clinically stable and without evidence of valve dysfunction. Valve size ranged from 19 to 31 mm, and ejection fraction ranged from 30% to 75%. With the parasternal long-axis view, the left ventricular outflow diameter measured just proximal to the prosthetic valve correlated well with valve size (r = 0.92). Doppler-derived maximal gradients ranged from 9 to 71 mm Hg. Effective prosthetic aortic valve area by the continuity equation ranged between 0.73 cm2 for a 19-mm valve and 4.23 cm2 for a 31-mm valve. With analysis of variance, effective orifice area differentiated various valve sizes (p less than 10(-14)) better than did gradients alone (p = 0.003) and correlated better with actual valve orifice area (r = 0.83 versus - 0.40). A Doppler velocity index, the ratio of peak velocity in the left ventricular outflow to that of the aortic jet, averaged 0.41 +/- 0.09 and was less dependent on valve size (r = 0.43). Thus, the continuity equation can be applied to the assessment of prosthetic St. Jude valves in the aortic position. By accounting for flow through the valve, it provides an improved assessment over the sole use of gradients in the evaluation of prosthetic valve function.
To assess the reliability of Doppler ultrasound for detecting serial changes in cardiac output in response to experimental interventions, the day to day variability of the minute distance of aortic flow was determined in seven normal subjects maintained in a tightly controlled environment with regard to diet and activities. Measurements were made at the same time on 5 to 6 sequential days from an apical window with use of both continuous wave and pulsed wave Doppler techniques. Two statistical measures of reliability were calculated, the intraclass coefficient of correlation (R), which varies between 0 (null reliability) and +1 (perfect reliability), and the 95% confidence interval for the error-free value of a single measurement. For sequential measurements of arterial pressure, 24 h urinary volume and sodium excretion and body weight, the intraclass coefficients of correlation ranged from 0.85 to 0.99, indicating low day to day variability consistent with tight environmental control. Continuous and pulsed wave modes were proved equally and highly reliable for measuring minute distance of aortic flow. However, continuous wave Doppler ultrasound provided acceptable signals more frequently than did the pulsed wave technique. For continuous wave Doppler ultrasound, R was 0.87 (p less than 0.00001); the 95% confidence interval was +/- 1.81 m/min (or 11% of the mean of all measurements), which indicates that this method can be used in a single individual to detect a greater than 11% change in minute distance measured once before and after an intervention.(ABSTRACT TRUNCATED AT 250 WORDS)
Transthoracic Doppler echocardiography examination has become an integral part of the investigations performed in patients with mitral valve prostheses. The limitations of the transthoracic approach are well documented. Transesophageal echocardiography provides a unique window for achieving a clear view of the mitral prosthesis.
This study shows the usefulness of transesophageal echocardiography in clinical practice for assessment of patients with a mitral valve prosthesis. This technique demonstrated an abnormality in 48% of patients who had normal results on transthoracic examination. The overall sensitivity of transesophageal echocardiography was 96%.
Transesophageal echocardiography constitutes an essential part of a comprehensive two-dimensional/Doppler echocardiographic examination in patients with suspected malfunction of mitral prostheses.
It has previously been demonstrated that predictable changes occur in mitral flow velocities under different loading conditions. The purpose of this study was to relate changes in pulmonary venous and mitral flow velocities during different loading conditions as assessed by transesophageal echocardiography in the operating room. Nineteen patients had measurements of hemodynamics, that is, mitral and pulmonary vein flow velocities during the control situation, a decrease in preload by administration of nitroglycerin, an increase in preload by administration of fluids, and an increase in afterload by infusion of phenylephrine. There was a direct correlation between the changes in the mitral E velocity and the early peak diastolic velocity in the pulmonary vein curves (r = 0.61) as well as a direct correlation between the deceleration time of the mitral and pulmonary venous flow velocities in early diastole (r = 0.84). This indicates that diastolic flow velocity in the pulmonary vein is determined by the same factors that influence the mitral flow velocity curves. A decrease in preload caused a significant reduction in the initial E velocity and prolongation of deceleration time, and an increase in preload caused an increase in E velocity and shortening of deceleration time. An increase in afterload produced a variable effect on the initial E velocity and deceleration time and was dependent on the left ventricular filling pressure. The change in systolic forward flow velocity in the pulmonary vein was directly proportional to the change in cardiac output (r = 0.60). The pulmonary capillary wedge pressure correlated best with the flow velocity reversal in the pulmonary vein at atrial contraction (r = 0.81). Use of pulmonary vein velocities in conjunction with mitral flow velocities can help in understanding left ventricular filling.
Doppler echocardiography is used in the noninvasive evaluation of mitral valve prostheses using parameters heretofore validated primarily for native valves. Accordingly, this study was designed to examine the validity and relative usefulness of valve gradient and area measurements in a group of 26 patients (17 women, 9 men, mean age 62 +/- 8 years), 19 +/- 4 months after implantation of different sizes (25 to 31 mm) of a given type of bioprosthesis. Areas obtained with both the continuity equation, using stroke volume measured in the left ventricular outflow tract, and the pressure half-time method are compared to known prosthetic areas derived from an in vitro hydraulic model. Areas calculated by the continuity equation correlate well with in vitro areas (r = 0.82, standard error of the y estimate = 0.1 cm2, p less than 0.001), and are within the range of predicted in vitro values in 92% of cases. Areas derived by the pressure half-time method do not correlate with in vitro areas (r = 0.15, p greater than 0.3) or continuity equation areas (r = 0.23, p greater than 0.2), and are above the range of predicted values in 69% of cases. Correlations are also found between continuity equation areas and the peak and mean valvular gradients (r = 0.59, p less than 0.005 and r = -0.63, p less than 0.0005, respectively). Taking the effect of cardiac output on gradients into account results in projected relations between indexed prosthetic areas and the pressure gradients at rest and during exercise.(ABSTRACT TRUNCATED AT 250 WORDS)
In 128 patients with apparently normally functioning prosthetic valves (n = 136) in the aortic position (n = 79) and the mitral position (n = 57), the prevalence of transprosthetic regurgitant flow was studied by use of transthoracic and transesophageal two-dimensional color-coded Doppler echocardiography. With the transthoracic approach, regurgitant flow was detected in early systole or diastole for 28% of the mitral prostheses and for 29% of the aortic prostheses. With transesophageal color-coded Doppler echocardiography, regurgitant jets were visualized for 95% of the mitral prostheses and for 44% of the aortic prostheses. In 40% of the Björk-Shiley prostheses and 88% of the St. Jude Medical prostheses in the mitral position, more than one jet with an eccentric origin was detected, whereas in bioprostheses only one centrally localized regurgitant jet was noted. The regurgitant jet length was 22 +/- 2 mm in mitral prostheses and 12 +/- 2 mm in aortic prostheses. The jet area was 154 +/- 31 mm2 in mitral prostheses and 61 +/- 26 mm2 in aortic prostheses. Jets of this size and frequency have to be considered a normal finding and the equivalent of regurgitant flow known from in vitro studies. We conclude that only transesophageal color-coded Doppler echocardiography seems to be a reliable method for following up mitral valve prostheses to detect and differentiate regurgitant jets. For aortic valve prostheses the advantage of transesophageal color-coded Doppler echocardiography does not seem to be as obvious as the advantage for mitral prostheses.
Mitral valve areas determined by Doppler pressure half-time were compared with areas obtained by planimetry in two groups of patients with mitral stenosis: 24 patients without aortic regurgitation and 32 patients with more than grade 1 aortic regurgitation. The severity of aortic regurgitation was assessed by color flow mapping; 17 patients had grade 2, 10 had grade 3 and 5 had grade 4 aortic regurgitation. Regression equations for pressure half-time area versus planimetry mitral valve area were calculated separately for the aortic regurgitation (r = 0.88) and the nonaortic regurgitation group (r = 0.86); analysis of covariance revealed a significant (p less than 0.001) difference between the two groups leading to overestimation of planimetry area by the pressure half-time method in the aortic regurgitation group. The mitral valve areas in the group without regurgitation were best calculated with the expression 239/T1/2 (r = 0.77) as compared with a best fit of 195/T1/2 (r = 0.85) for the aortic regurgitation group. To elucidate the mechanisms affecting pressure half-time in aortic regurgitation, an in vitro model of mitral inflow in the presence of varying regurgitant volumes and different ventricular chamber compliances was used. Aortic regurgitation shortened directly measured pressure half-time proportional to the regurgitant fraction but an increase in left ventricular compliance could offset this effect. Finally, in a mathematic model of mitral inflow the competing effects of aortic regurgitation and chamber compliance could be confirmed. In conclusion, aortic regurgitation results clinically in a significant net shortening of pressure half-time leading to mitral valve area overestimation. However, the effect is moderate and individually unpredictable because of changes in chamber compliance.
To evaluate a simple noninvasive means of estimating right atrial (RA) pressure, the respiratory motion of the inferior vena cava (IVC) was analyzed by 2-dimensional echocardiography in 83 patients. Expiratory and inspiratory IVC diameters and percent collapse (caval index) were measured in subcostal views within 2 cm of the right atrium. Parameters were correlated with RA pressure by flotation catheter within 24 hours of the echocardiogram (38 were simultaneous). Correlations between RA pressure (range 0 to 28 mm Hg), expiratory and inspiratory diameters and caval index were 0.48, 0.71 and 0.75, respectively. Of 48 patients with caval indexes less than 50%, 41 (89%) had RA pressure greater than or equal to 10 mm Hg (mean +/- standard deviation, 15 +/- 6), while 30 of 35 patients (86%) with caval indexes greater than or equal to 50% had RA pressure less than 10 mm Hg (mean 6 +/- 5). Sensitivity and specificity for discrimination of RA pressure greater than or equal to or less than 10 mm Hg were maximized at the 50% level of collapse. Thus, IVC respiratory collapse on echocardiography is easily imaged and can be used to estimate RA pressure. A caval index greater than or equal to 50% indicates RA pressure less than 10 mm Hg, and caval indexes less than 50% indicate RA pressure greater than or equal to 10 Hg.
To evaluate possible causes of discrepancy between Doppler and catheter gradients across prosthetic valves, five sizes (19-27 mm) of St. Jude and Hancock valves were studied in an aortic pulsatile flow model. Catheter gradients at multiple sites distal to the valve were compared with simultaneously obtained Doppler gradients. In the St. Jude valve, significant differences between Doppler and catheter gradients measured 30 mm downstream from the valve were found: Doppler gradients exceeded peak catheter gradients of 10 mm Hg or more by 81 +/- 35% (15 +/- 3.6 mm Hg), and mean catheter gradients by 71 +/- 11% (10.3 +/- 2.5 mm Hg). When the catheter was pulled back through the tunnel-like central orifice of the valve, high localized gradients at the valve plane and significant early pressure recovery were found. When the catheter was pulled back through the large side orifices, gradients at the same level were only 46 +/- 6% of the central orifice gradients (mean difference, 7.6 +/- 4.5 mm Hg). Doppler peak and mean gradients showed excellent agreement with the highest central orifice catheter gradients (mean difference, 1.0 +/- 3.1 and 0.9 +/- 1.5 mm Hg, respectively). A significantly better agreement between Doppler and catheter gradients at 30 mm was found for the Hancock valve, although Doppler peak and mean gradients were still slightly greater than catheter gradients. Doppler gradients exceeded catheter gradients by 18 +/- 10% (3.4 +/- 1.9 mm Hg) and 13 +/- 11% (2.1 +/- 0.9 mm Hg), respectively. When the catheter was pulled back through the valve, the highest gradients were found approximately 20 mm distal to the valve ring.(ABSTRACT TRUNCATED AT 250 WORDS)
To determine whether pulmonary venous flow and mitral inflow measured by transesophageal pulsed Doppler echocardiography can be used to estimate mean left atrial pressure (LAP), we prospectively studied 47 consecutive patients undergoing cardiovascular surgery. We correlated Doppler variables of pulmonary venous flow and mitral inflow with simultaneously obtained mean LAP and changes in pressure measured by left atrial or pulmonary artery catheters. Among the pulmonary venous flow variables, the systolic fraction (i.e., the systolic velocity-time integral expressed as a fraction of the sum of systolic and early diastolic velocity-time integrals) correlated most strongly with mean LAP (r = -0.88). Of the mitral inflow variables, the ratio of peak early diastolic to peak late diastolic mitral flow velocity correlated most strongly with mean LAP (r = 0.43), but this correlation was not as strong as that with the systolic fraction of pulmonary venous flow. Similarly, changes in the systolic fraction correlated more strongly with changes in mean LAP (r = -0.78) than did changes in the ratio of peak early diastolic to peak late diastolic mitral inflow velocity (r = 0.68). We conclude that in the surgical setting observed, pulmonary venous flow from transesophageal pulsed Doppler echocardiography can be used to estimate mean LAP. This technique may provide a rapid, simple, and relatively noninvasive means of gauging this variable in patients undergoing intraoperative transesophageal echocardiography.
Evaluation of diastolic filling of the heart has been difficult because of its complexity and the numerous interrelated contributing factors. Previous determinations have depended on high-fidelity, invasive measurements of instantaneous pressure, volume, mass, and wall stress, which could not be done on a routine clinical basis. With the advent of Doppler echocardiography, intracardiac blood flow velocities can now be noninvasively assessed. For application of this technique to evaluation of diastolic function in patients with heart disease, it is necessary to understand what the Doppler-derived variables represent. It is also necessary to know how they are affected by changes in loading conditions and changes in myocardial relaxation. In this review, we provide an interpretation of the mitral valve, tricuspid valve, and systemic and pulmonary venous inflow velocities in the normal patient and in various disease states.
Abnormal respiratory variation in diastolic filling has been reported in patients with cardiac tamponade. To determine the characteristic diastolic filling abnormalities in this disorder, we recorded left ventricular isovolumic relaxation time and transvalvular and hepatic venous flow velocities by pulsed-wave Doppler echocardiography in 28 patients with pericardial effusion (16 with and 12 without cardiac tamponade) and 20 normal control subjects. The phase of respiration was recorded simultaneously with all profiles. In 13 of the 16 patients with cardiac tamponade, Doppler examination was repeated after pericardiocentesis. In patients with cardiac tamponade, respiratory variations in transvalvular flow velocities and isovolumic relaxation time were substantially increased in comparison with values in normal subjects, patients without tamponade, and those who had undergone pericardiocentesis. An exaggerated expiratory decrease in diastolic forward flow and increase in reverse flow in the hepatic vein also were characteristic of patients with cardiac tamponade. Thus, Doppler echocardiography is an additional noninvasive means of detecting hemodynamic compromise in patients with pericardial effusion.
Studies correlating prosthetic valve gradients determined by continuous wave Doppler echocardiography with gradients obtained by cardiac catheterization have, to date, been limited to patients with mitral and tricuspid prostheses or have compared nonsimultaneous measurements. Simultaneous Doppler and catheter pressure gradients in 36 patients (mean age, 63 +/- 13 years) with 42 prosthetic valves (20 aortic, 20 mitral, one tricuspid, and one pulmonary) were studied. Catheter gradients were obtained using a dual-catheter technique. The simultaneous pressure tracings and Doppler flow velocity profiles were digitized at 10-msec intervals to derive the corresponding maximal and mean gradients. The correlation between the maximal Doppler gradient and the simultaneously measured maximal catheter gradient was 0.94 (SEE = 6), and that between the Doppler gradient and the simultaneously measured mean catheter gradient was 0.96 (SEE = 3). There were no significant differences in correlation between gradients for the 32 mechanical valves (maximal gradients: r = 0.95, SEE = 6; mean gradients: r = 0.96, SEE = 3) and the 10 bioprosthetic valves (maximal gradients: r = 0.89, SEE = 6; mean gradients: r = 0.93, SEE = 3). In patients with mitral prostheses, Doppler gradients correlated well with the corresponding catheter gradients obtained with direct measurement of left atrial pressure (maximal gradients: r = 0.96, SEE = 2; mean gradients: r = 0.97, SEE = 1.2). A close correlation between corresponding Doppler and catheter gradients also was found in patients with aortic prostheses (maximal gradients: r = 0.94, SEE = 6; mean gradients: r = 0.94, SEE = 3). Thus, continuous wave Doppler echocardiography can accurately predict the pressure gradient across prosthetic valves.
To evaluate the influence of left ventricular chamber stiffness and relaxation on Doppler echocardiographic indexes of diastolic function, 35 patients (mean age 60 ± 12 years) were examined; 24 had coronary artery disease and 11 (Group I) had no cardiovascular disease. Micromanometer left ventricular pressure was recorded simultaneously with Doppler echocardiograms of mitral valve inflow and M-mode echocardiograms of left ventricular diameter. The chamber stiffness constant (k) was derived from the pressure-diameter relation. Relaxation was assessed by the isovolumic relaxation time constant (τ) derived from the exponential left ventricular pressure decay. The patients with coronary artery disease were classified into two groups on the basis of complete (Group II; n = 10) and incomplete (Group III; n = 14) relaxation.
Doppler ultrasound recordings of mitral, tricuspid, aortic, and pulmonary flow velocities, and their variation with respiration, were recorded in 12 patients with a restrictive cardiomyopathy and seven patients with constrictive pericarditis. Twenty healthy adults served as controls. The patients with constrictive pericarditis showed marked changes in left ventricular isovolumic relaxation time and in early mitral and tricuspid flow velocities at the onset of inspiration and expiration. These changes disappeared after pericardiectomy and were not seen in patients with restrictive cardiomyopathy or in normal subjects. The deceleration time of early mitral and tricuspid flow velocity was shorter than normal in both groups, indicating an early cessation of ventricular filling, but only patients with restrictive cardiomyopathy showed a further shortening of the tricuspid deceleration time with inspiration. Diastolic mitral and tricuspid regurgitation was also more common in the patients with restrictive cardiomyopathy. These results suggest that patients with constrictive pericarditis and restrictive cardiomyopathy can be differentiated by comparing respiratory changes in transvalvular flow velocities. In addition, although baseline hemodynamics in the two groups were similar, characteristic changes were seen with respiration that suggest differentiation of these disease states may also be possible from hemodynamic data.
Estimation of the orifice area is of major importance in the timing of valve dilation or surgery in patients with mitral stenosis. Determination of the area has traditionally been accomplished at cardiac catheterization by the Gorlin equation. The valve area can also be estimated noninvasively with Doppler echocardiographic measurements of the pressure half-time, which is inversely proportional to the area. This method has gained widespread acceptance, but its accuracy has recently been questioned and factors other than reduction of orifice area appear to modify the pressure half-time. In the present study, the influence of left ventricular stiffness (defined as diastolic pressure rise per milliliter of mitral flow) and peak atrioventricular pressure difference on the pressure half-time was examined both in a hydraulic model and by review of data from 35 patients with mitral stenosis. Left ventricular stiffness less than 0.13 mm Hg/ml was considered normal. In the model study, the orifice area correlated only moderately with inverted pressure half-time (1/PHT) (r = 0.67). By multiple linear regression, inverted pressure half-time was shown to be dependent on valve area, chamber stiffness and peak pressure difference (R = 0.89), area and stiffness being most important (R = 0.85). In the clinical study, an increased ventricular stiffness was found in 22 of the 35 patients. The pressure half-time method overestimated the Gorlin-derived area by an average of 72% in these patients compared with only 10% in 13 patients with normal stiffness (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)
Doppler echocardiography plays an important role in the evaluation of patients with prosthetic valves. The evaluation of flow velocities across prosthetic valves is more complicated compared with native valves, and flow velocities are specific for various types, positions, and sizes of prostheses. Because all prosthetic valves are at least mildly stenotic and a significant proportion is regurgitant, information regarding normally functioning prosthetic valves is important. Eighteen studies resulting in data on 1105 patients with normally functioning prosthetic valves were reviewed. Significant differences among the various types and sizes of prosthetic valves were found in both the aortic and mitral positions. The results are summarized in tables and figures that can be used for reference in a clinical laboratory.
A theory is presented elucidating factors that influence the pressure half-time. By combining the Bernoulli and continuity equations and making certain assumptions about the shape of the atrioventricular pressure difference decay, it can be shown that valve area, volume transported across that area, and initial pressure difference influence the pressure half-time according to a formula in which the pressure half-time is related to V/(Ao square root of delta po), where V is the transported volume across the orifice with the area Ao, and delta po is the initial pressure difference across that area. In a subsequent hydraulic model experiment pressure half-time was determined for three different hole areas, with various initial volumes and initial pressure gradients. We did not obtain a unique relation between the pressure half-time and area. Instead the results supported our theory, and we found a close linear relationship between area and V/(T0.5 square root of delta po) (correlation coefficient [r] = 0.998), as predicted in the theory (T0.5 = pressure half-time). Clinical examples in which the pressure half-time may be misleading in the assessment of severity of mitral stenosis are presented.
Two Doppler methods, the pressure half-time method proposed by Hatle and the method based on the equation of continuity, were used to estimate stenotic mitral valve area noninvasively, and the accuracy of these methods was examined in patients with and without associated aortic regurgitation. Mitral valve area determined at catheterization by the Gorlin formula was used as a standard of reference. The study population consisted of 41 patients with mitral stenosis, and 20 of the 41 patients had associated aortic regurgitation. According to the equation of continuity, mitral valve area was determined as a product of aortic or pulmonic annular cross-sectional area and the ratio of time velocity integral of aortic or pulmonic flow to that of the mitral stenotic jet. Mitral valve area was determined by the pressure half-time method as 220/pressure half-time, the time from the peak transmitral velocity to one-half the square root of the peak velocity on the continuous-wave Doppler-determined transmitral flow velocity pattern. The pressure half-time method tended to overestimate catheterization measurements, and the correlation coefficient for this relation was .69 (SEE = 0.44 cm2). The correlation coefficient improved to .90 when the patients with associated aortic regurgitation were excluded. Mitral valve areas determined by the continuity equation method correlated well with catheterization measurements at a correlation coefficient of .91 (SEE = 0.24 cm2), irrespective of the presence of aortic regurgitation. The ratio of the time-velocity integral or aortic or pulmonic flow to the time-velocity integral of mitral stenotic jet also correlated well with mitral valve area determined by catheterization at a correlation coefficient of .84 (SEE = 0.10).(ABSTRACT TRUNCATED AT 250 WORDS)
This study was undertaken to compare the accuracies of the two-dimensional echocardiographic (2DE) and Doppler pressure half-time methods for the noninvasive estimation of cardiac catheterization measurements of mitral valve area in patients with pure mitral stenosis both with and without a previous commissurotomy. Data were retrospectively obtained from 74 consecutive patients who underwent cardiac catheterization within a 30 month period for evaluation of mitral stenosis, and who had two-dimensional echocardiograms performed before catheterization. Six patients (8.1%) had technically inadequate 2DE images and their data were excluded from analysis. Two of these patients had undergone commissurotomy, while the remaining four had not. Continuous-wave Doppler echocardiographic examinations were attempted in 45 patients and adequate measurements of pressure half-times were obtained in all patients studied. Mitral valve area by two-dimensional echocardiography was measured as the planimetered area along the inner border of the smallest mitral orifice visualized during short-axis scanning, while pressure half-time was calculated as the interval between the peak transmitral velocity and velocity/square root 2 as measured from the envelope of the Doppler spectral signal. Calculations from catheterization represented the minimal valve area at rest as derived from the Gorlin formula with the use of pressure gradients and thermodilution measurements of cardiac output. Thirty-seven of the patients had had a previous mitral commissurotomy a mean of 11.2 +/- 5.4 years before, while the remaining 37 patients were previously unoperated. Mean valve area as determined at catheterization for the total group of patients ranged from 0.37 to 2.30 cm2 (mean = 1.08 +/- 0.42 cm2).(ABSTRACT TRUNCATED AT 250 WORDS)
Aortic regurgitation and mitral stenosis are hemodynamically similar, insofar as both result in passive ventricular filling across a narrow orifice driven by a declining pressure gradient. Because mitral stenosis is successfully characterized by Doppler ultrasound determination of the velocity half-time, or time constant, aortic regurgitation might be quantified in an analogous fashion. Eighty-six patients with diverse causes of aortic regurgitation underwent continuous wave Doppler examination before cardiac catheterization or urgent aortic valve replacement. The Doppler velocity half-time was defined as the time required for the diastolic aortic regurgitation velocity profile to decay by 29%, whereas catheterization pressure half-time was calculated as the time required for transvalvular pressure to decay by 50%. Doppler velocity and catheterization pressure half-times were linearly related (r = 0.91). Doppler velocity half-times were inversely related to regurgitant fraction (r = -0.88). Angiographic severity (1+ = mild to 4+ = severe) was also inversely related to pressure and velocity half-time; a Doppler half-time threshold of 400 ms separated mild (1+, 2+) from significant (3+, 4+) aortic regurgitation with high specificity (0.92) and predictive value (0.90). The Doppler velocity half-time was independent of pulse pressure, mean arterial pressure, ejection fraction and left ventricular end-diastolic pressure. Estimation of transvalvular aortic pressure half-time utilizing continuous wave Doppler ultrasound is a reliable and accurate method for the noninvasive evaluation of the severity of aortic regurgitation.
Measurements of mitral and aortic valve flows were obtained with two-dimensional Doppler echocardiography in 25 patients with isolated mitral (n = 19) or aortic (n = 6) regurgitation and regurgitant fraction was calculated as the difference between the two flows divided by the flow through the regurgitant valve. Results were compared with measurements of regurgitant fraction determined by combined left ventricular angiography and thermodilution. Regurgitant fraction averaged 56 +/- 18% (range 19 to 79) by Doppler echocardiography and 48 +/- 17% (range 13 to 72) by angiography. A significant correlation was observed between the two methods (r = 0.91; SEE = 7%). In contrast, no significant correlation was found between regurgitant fraction measured by either method and the angiographic 1+ to 4+ qualitative classification of regurgitation. Doppler echocardiography appears to be an accurate method for the non-invasive quantification of severity of regurgitation in isolated left-sided valve lesions.
Doppler echocardiography enables noninvasive determination of blood velocity and flow area through which quantitation of blood flow in vessels and across valvular orifices can be achieved. The stroke volume is rendered as the product of the flow area and the area beneath the velocity curve; on taking the heart rate into consideration, the cardiac output can be calculated. Essentially, this method can be used in the region of all four cardiac valves, the ascending aorta and the pulmonary artery. For calculation of the mitral and tricuspid velocity, the sample volume is positioned in the region of the tips of the leaflets or in the valve anulus. The flow area is most frequently calculated from the diameter of the valve anulus under the assumption of a circular cross-section. Additionally, in some studies, with respect to correction for area changes during diastole, separation of the leaflets in the M-mode echocardiogram has been employed. Determination of the right ventricular output is accomplished through the combination of the blood flow velocity in the pulmonary artery and the cross-sectional area of this vessel, the right ventricular outflow tract or the pulmonic anulus. To calculate flow in the ascending aorta, both pulsed and continuous-wave Doppler techniques have been employed and the diameter of the ascending aorta or the aortic root is derived echocardiographically. Comparative studies of the various methods show that measurement of flow in the region of the aortic anulus yields results somewhat superior to that of the other methods. Possible sources of error in these methods result from simplifying assumptions with respect to calculation of the area of flow, that is, equating the anatomical area with the area of flow, circular or elliptical cross-sectional models, temporal constancy of the areas as well as the velocities, that is, constant position of the sample volume, flat velocity profile and neglect of angle deviations.
A number of reports have described different Doppler echocardiographic methods to calculate left ventricular stroke volume and cardiac output, but the clinical application of the noninvasive measurements of cardiac function remains in the early stages of development. This slow dissemination may be partly explained by the varying success of these ultrasound methods in determining accurate left ventricular stroke volume. The purpose of this study was to improve the simplicity and accuracy of Doppler stroke volume determination so that it could be more easily applied to patient management. Stroke volume was measured using the product of the integral of aortic velocity obtained by continuous wave Doppler technique and the M-mode tracing of the aortic valve, validating the data against cardiac output obtained by thermodilution technique in 41 patients (r = 0.95, SEE = 7 cc). Intra- and interobserver variability was between 9 and 11%. The results of different sampling sites and the temporal relation between Doppler and thermodilution measurements were also studied. Analysis of 21 patients who had M-mode and two-dimensional echocardiographic studies of the aortic root revealed that the method using M-mode measurement of aortic valve area was most accurate in determining left ventricular stroke volume (r = 0.94, SEE = 10 cc), stroke volume being overestimated when area measurements of the ascending aorta were used. In conclusion, maximal ascending aortic velocity determined by continuous wave Doppler echocardiography with M-mode measurement of aortic valve area can be used to calculate left ventricular stroke volume and cardiac output. The simplicity and practicality of this method should enhance the clinical application of Doppler echocardiography as a noninvasive monitoring technique.
In 30 patients with aortic stenosis, 14 of whom also had significant aortic regurgitation, the velocities in the stenotic jet (V') and below the valve (V) were recorded by Doppler ultrasound. With two-dimensional echocardiography, two subvalvular areas (A) were calculated from leading-to-leading edge ("large") and trailing-to-leading edge ("inner") diameter measurements. The aortic valve area was calculated by the equation of continuity (A' = A X peak V/peak V') and by calculating stroke volume below the valve [A X integral of V (t) and dividing by the integral of V' (t) (= A"). Based on cardiac output estimations from single-plane angiographic images, Gorlin's formula was used to calculate invasive valve areas. In patients with no or mild aortic regurgitation a second invasive estimate was based on cardiac output measured by the Fick method. The best correlation was found when A' (with "large" diameter) was compared with invasive results based on cardiac output measured by the Fick method (r = .89, SEE +/- 0.12, n = 16); the worst was found when A" (with "large" diameter) was compared with invasive results based on cardiac output measurements by single-plane angiography (r = .80, SEE +/- 0.20, n = 30). The results indicate that valve area in patients with aortic stenosis can be reliably estimated noninvasively, even in those with significant aortic regurgitation.
Laminar flow through a conduit is equal to the mean velocity times the cross-sectional area of the orifice. Therefore, volume is equal to the time-velocity integral multiplied by the cross-sectional area. In aortic stenosis, flow in the stenotic jet is laminar and the aortic valve area should be equal to the volume of blood ejected through the valve divided by the time-velocity integral of the aortic jet velocity recorded by continuous-wave Doppler echocardiography. To test whether this concept can be used to accurately determine aortic valve area noninvasively by the Doppler method, 39 patients (age 35 to 82 years, mean 63) underwent pulsed Doppler combined with two-dimensional echocardiography for measurement of stroke volume at the aortic, pulmonic, and mitral anulus as well as continuous-wave Doppler recording of the aortic jet. Aortic valve area determined at cardiac catheterization by the Gorlin equation ranged between 0.4 and 2.07 cm2 (mean 0.89 +/- 0.45). Doppler-derived valve area, determined with the stroke volume value from either the aortic, pulmonic, or mitral anulus, correlated well with the area determined at cardiac catheterization (r = .95, .97, and .96, respectively). A simplified method for measuring aortic valve area derived as the cross-sectional area of the aortic anulus times peak velocity just proximal to the aortic valve divided by peak aortic jet velocity correlated well with measurements obtained at cardiac catheterization (r = .94). An excellent separation between critical and noncritical aortic stenosis was seen using either one of the Doppler methods.(ABSTRACT TRUNCATED AT 250 WORDS)
The severity of aortic stenosis was evaluated by Doppler echocardiography in 48 adults (mean age 67 years) undergoing cardiac catheterization. Maximal Doppler systolic gradient correlated with peak to peak pressure gradient (r = 0.79, y = 0.63x + 25.2 mm Hg) and mean Doppler gradient correlated with mean pressure gradient (r = 0.77, y = 0.59x + 10.0 mm Hg) by manometry. The transvalvular pressure gradient is flow dependent, however, and associated left ventricular dysfunction was common in our patients (33%). Thus, of the 32 patients with an aortic valve area less than or equal to 1.0 cm2 at catheterization, 6 (19%) had a peak Doppler gradient less than 50 mm Hg. To take into account the influence of volume flow, aortic valve area was calculated as stroke volume, measured simultaneously by thermodilution, divided by the Doppler systolic velocity integral in the aortic jet. Aortic valve areas calculated by this method were compared with results at catheterization in the total group (r = 0.71). Significant aortic insufficiency was present in 71% of the population. In the subgroup without significant coexisting aortic insufficiency, closer agreement of valve area with catheterization was noted (n = 14, r = 0.91, y = 0.83x + 0.24 cm2). Transaortic stroke volume can be determined noninvasively by Doppler echocardiographic measures in the left ventricular outflow tract, just proximal to the stenotic valve. Aortic valve area can then be calculated as left ventricular outflow tract cross-sectional area times the systolic velocity integral of outflow tract flow, divided by the systolic velocity integral in the aortic jet.(ABSTRACT TRUNCATED AT 250 WORDS)
To more precisely measure the beat to beat and instantaneous pressure gradients across outflow stenotic lesions, simultaneous Doppler and dual catheter pressure gradient measurements were performed in 95 patients (mean age 42 years, range 1.5 to 85). There were 38 right ventricular and 62 left ventricular outflow obstructive lesions. Forty-nine patients also had a nonsimultaneous Doppler study performed within 7 days before catheterization. The simultaneous pressure waveforms and Doppler spectral velocity profiles were digitized at 10 ms intervals deriving maximal, mean and instantaneous gradients (mm Hg). For simultaneous maximal Doppler and catheter gradient measurements, the correlation coefficient (r) was 0.95 (SEE = 10 mm Hg), for Doppler and catheter mean gradients it was 0.94 (SEE = 8 mm Hg) and for maximal Doppler and peak to peak catheter gradients it was 0.92 (SEE = 13 mm Hg). The correlation of maximal and mean Doppler gradients with the respective catheter gradients was similarly high when the right and left ventricular outflow lesions were analyzed separately. However, the maximal Doppler gradient was significantly higher than the peak to peak catheter gradient. This was more evident with left ventricular outflow stenotic lesions. The correlation of the outpatient maximal Doppler and catheter gradients (r = 0.80, SEE = 17 mm Hg) was significantly lower than the simultaneous correlation (r = 0.96, SEE = 10 mm Hg) in the 49 patients with two Doppler studies. Continuous wave Doppler echocardiography accurately measures the instantaneous pressure gradient across both left and right ventricular outflow obstructive lesions. The maximal Doppler gradient should not be equated with the peak to peak catheter gradient.(ABSTRACT TRUNCATED AT 250 WORDS)
To determine the relationship between Doppler-derived flow velocity through the mitral anulus and angiographic parameters of left ventricular filling, 30 patients were studied by two-dimensional echocardiography combined with pulsed Doppler echocardiography followed within 1 hr by left ventricular angiography. The average heart rate for each test was 69 beats/min. Doppler-derived parameters included: early peak diastolic velocity (E) and peak atrial velocity, peak filling rate computed as E X cross-sectional area of the mitral anulus derived from the annular diameter, normalized peak filling rate computed as peak filling rate divided by the left ventricular end-diastolic volume determined by two-dimensional echocardiography, and half filling fraction derived from the time-velocity integral of the Doppler-determined velocity curve. Frame-by-frame left ventricular volumes were obtained throughout diastole from single-plane cineangiograms. A volume-time curve with its derivative was generated by computer processing from which peak filling rate, normalized peak filling rate, and half filling fraction were measured. Morphologically, the Doppler-derived velocity profile resembled the derivative of the angiographic volume curve. In patients with reduced angiographic peak filling rates, early peak diastolic velocity was often decreased less than 45 cm/sec with a relative increase in peak atrial velocity resulting in an early peak diastolic velocity to peak atrial velocity ratio less than 1.0. There were no significant differences in mean values for peak filling rate, normalized peak filling rate, and half filling fraction by Doppler echocardiography vs angiography (296 vs 283 ml/sec, 1.9 vs 2.0 sec-1 and 0.55 vs 0.55, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)
Studies of the correlation of aortic valve gradient determined by continuous-wave Doppler echocardiography and that determined at catheterization have, to date, involved young patients and nonsimultaneous measurements. We therefore obtained simultaneous Doppler echocardiographic and catheter measurements of pressure gradient in 100 consecutive adults (mean age 69, range 50 to 89 years). In 63 patients pressure measurements were obtained with dual-catheter techniques and in 37 they were obtained by withdrawal of the catheter from the left ventricle to the ascending aorta. Forty-six of these patients also underwent an outpatient Doppler study 7 days or less before catheterization. The simultaneous pressure waveforms and Doppler spectral velocity profiles were digitized at 10 msec intervals and maximum, mean, and instantaneous gradients (mm Hg) were derived for each. The correlation between the Doppler-determined gradient and the simultaneously measured maximum catheter gradient was r = .92 (SEE = 15 mm Hg), that between the Doppler-determined and mean catheter gradient was r = .93 (SEE = 10 mm Hg), and that between the Doppler and peak-to-peak catheter gradient was r = .91 (SEE = 14). The correlation between the nonsimultaneously Doppler-determined gradient and the maximum gradient measured by catheter was not as strong (r = .79, SEE = 24). The continuous-wave Doppler echocardiographic velocity profile represents the instantaneous transaortic pressure gradient throughout the cardiac cycle. The best correlation with continuous-wave Doppler-determined gradient was obtained with maximum and mean gradients measured by catheter. Continuous-wave Doppler echocardiography can be used to reliably predict the pressure gradient in adults with calcific aortic stenosis.
Simultaneous continuous wave Doppler echocardiography and right-sided cardiac pressure measurements were performed during cardiac catheterization in 127 patients. Tricuspid regurgitation was detected by the Doppler method in 117 patients and was of adequate quality to analyze in 111 patients. Maximal systolic pressure gradient between the right ventricle and right atrium was 11 to 136 mm Hg (mean 53 +/- 29) and simultaneously measured Doppler gradient was 9 to 127 mm Hg (mean 49 +/- 26); for these two measurements, r = 0.96 and SEE = 7 mm Hg. Right ventricular systolic pressure was estimated by three methods from the Doppler gradient. These were 1) Doppler gradient + mean jugular venous pressure; 2) using a regression equation derived from the first 63 patients (Group 1); and 3) Doppler gradient + 10. These methods were tested on the remaining 48 patients with Doppler-analyzable tricuspid regurgitation (Group 2). The correlation between Doppler-estimated and catheter-measured right ventricular systolic pressure was similar using all three methods; however, the regression equation produced a significantly better estimate (p less than 0.05). Use of continuous wave Doppler blood flow velocity of tricuspid regurgitation permitted determination of the systolic pressure gradient across the tricuspid valve and the right ventricular systolic pressure. This noninvasive technique yielded information comparable with that obtained at catheterization. Approximately 80% of patients with increased and 57% with normal right ventricular pressure had analyzable Doppler tricuspid regurgitant velocities that could be used to accurately predict right ventricular systolic pressure.
Two methods of measuring stroke volume and cardiac output with pulsed Doppler two-dimensional echocardiography were developed and validated against the thermodilution technique in 39 patients, 33 of which were in an intensive care unit. With the use of the apical four-chamber view, a mitral inflow method combined the velocity of left ventricular inflow at the mitral anulus with the cross-sectional area of the anulus calculated from its diameter at middiastole (area = pi r2). From the apical five-chamber view a left ventricular outflow method combined the velocity of left ventricular outflow with the cross-sectional area of the aortic anulus calculated from its diameter during early systole (parasternal long-axis view). Measurements with the mitral inflow and left ventricular outflow methods were obtained in 35 of 39 (90%) and 39 of 39 (100%) patients, respectively. Validation of the mitral method excluded patients with mitral regurgitation (n = 11) and validation of the left ventricular outflow method excluded those with aortic regurgitation (n = 4). Good correlations were observed between thermodilution and Doppler measurements of stroke volume and cardiac output for both the mitral anulus method (R = .96 and .87, respectively) and the left ventricular outflow method (R = .95 and .91, respectively). The results of the two methods correlated well with each other in patients without regurgitant valve lesions. A greater interobserver variability was observed with the mitral anulus method, which was related solely to greater variability in measuring the annular diameter.(ABSTRACT TRUNCATED AT 250 WORDS)
A noninvasive technique for assessing cardiac output (CO) was evaluated by comparing it with thermodilution determinations in patients in the intensive care unit. The new method uses pulsed ultrasound to measure aortic diameter and continuous-wave Doppler ultrasound to obtain aortic blood velocity. An initial study evaluating just the velocity measurement showed that changes of the Doppler index of output (DI) correlated well with those of thermodilution cardiac output (TDCO). Linear regression analysis yielded delta DI = 0.87 delta TDCO + 0.14 (r = 0.83, n = 95). Using a university research instrument these measurements were possible in 54 of 60 patients (90%). A second study using a prototype commercial device incorporated the diameter measurement. Ultrasonic cardiac output (UCO), calculated as the time integral of velocity multiplied by the aortic area, was compared to TDCO. The data, obtained from 45 of 53 patients (85%), are described by the linear regression UCO = 0.95TDCO + 0.38 (r = 0.94, n = 110) over a range of 2-11 l/min. Patients with aortic stenosis, aortic insufficiency or a prosthetic valve have been excluded from the second study due to conditions likely to violate the assumptions upon which the calculation of absolute cardiac output is based. These results indicate that accurate CO can be measured by noninvasive ultrasound in most patients. The technique may be useful for extended CO monitoring in acute care patients and for CO assessment in many other types of patients undergoing diagnostic studies and therapeutic interventions.
Two-dimensional echocardiography has proven very useful in assessing valvular heart disease, but the technique is limited in certain groups of patients and is unable to quantify a transvalvular pressure gradient. Advances in the Doppler ultrasound techniques have made it possible to noninvasively measure velocity of flow across a stenotic heart valve and to calculate the pressure gradient. A commercially available, continuous and pulse wave Doppler instrument was utilized to assess the transvalvular pressure gradient in patients with mitral and aortic stenosis and the transmitral pressure half-time to calculate mitra valve area. Thirty-five consecutive adult patients with suspected aortic stenosis and 30 adult patients with suspected mitral stenosis underwent Doppler ultrasound examination within 24 hours of cardiac catheterization. An adequate Doppler examination was obtained in 81% of the patients with aortic stenosis, with a correlation between the Doppler-derived transaortic gradient and the catheterization-derived gradient of 0.94. The Doppler-measured gradient accurately separated those patients with significant aortic stenosis (gradients of greater than 50 mm Hg) from those patients with noncritical aortic stenosis. Similarly, an adequate Doppler examination was obtained in 90% of the adult patients with mitral stenosis. There was also close correlation between the mitral valve area and mean pressure gradient measured by the Doppler technique and that obtained at the time of cardiac catheterization (r = 0.87 and 0.85, respectively). The Doppler technique proved to be useful in those patients who had also undergone prior mitral commissurotomy. This study confirms that the combined continuous pulse wave Doppler technique will serve as a valuable addition to the diagnostic capabilities offered by echocardiography.