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![Different types of P wave morphology. Typical examples of: Type 1 P wave morphology (A), Type 2 P wave morphology (B) and Type 3 P wave morphology (C). Type 3 morphology has previously been shown to be compatible with Bachmann's bundle block [20,21].](profile/Jonas-Carlson/publication/5920094/figure/fig1/AS:195335877074965@1423583110926/Different-types-of-P-wave-morphology-Typical-examples-of-Type-1-P-wave-morphology-A.png)
Different types of P wave morphology. Typical examples of: Type 1 P wave morphology (A), Type 2 P wave morphology (B) and Type 3 P wave morphology (C). Type 3 morphology has previously been shown to be compatible with Bachmann's bundle block [20,21].
Source publication
The study was designed to investigate the effect of different measuring methodologies on the estimation of P wave duration. The recording length required to ensure reproducibility in unfiltered, signal-averaged P wave analysis was also investigated. An algorithm for automated classification was designed and its reproducibility of manual P wave morp...
Citations
... Studies have shown high inter-and intraobserver agreement for manual PWP measurements, a good level of agreement with automated measurements, 82 and good reproducibility. 83,84 The short-term repeatability of PWPs had been previously reported: intraclass correlation coefficients were 0.78 for P-wave axis, 0.77 for maximum P area, and 0.58 for maximum P duration. Within-and between-visit Kappa for PTFV1 were 0.68 and 0.46, respectively. ...
Atrial cardiomyopathy, characterized by abnormalities in atrial structure and function, is associated with increased risk of adverse cardiovascular and neurocognitive outcomes, independent of atrial fibrillation. There exists a critical unmet need for a clinical tool that is cost-effective, easy to use, and that can diagnose atrial cardiomyopathy. P-wave parameters (PWPs) reflect underlying atrial structure, size, and electrical activation; alterations in these factors manifest as abnormalities in PWPs that can be readily ascertained from a standard 12-lead ECG and potentially be used to aid clinical decision-making. PWPs include P-wave duration, interatrial block, P-wave terminal force in V1, P-wave axis, P-wave voltage, P-wave area, and P-wave dispersion. PWPs can be combined to yield an index (P-wave índex), such as the morphology-voltage-P-wave duration ECG risk score. Abnormal PWPs have been shown in population-based cohort studies to be independently associated with higher risks of atrial fibrillation, ischemic stroke, sudden cardiac death, and dementia. Additionally, PWPs, either individually or in combination (as a P-wave índex), have been reported to enhance prediction of atrial fibrillation or ischemic stroke. To facilitate translation of PWPs to routine clinical practice, additional work is needed to standardize measurement of PWPs (eg, via semiautomated or automated measurement), confirm their reliability and predictive value, leverage novel approaches (eg, wavelet analysis of P waves and machine learning algorithms), and finally, define the risk-benefit ratio of specific interventions in high-risk individuals. Our ultimate goal is to repurpose the ubiquitous 12-lead ECG to advance the study, diagnosis, and treatment of atrial cardiomyopathy, thus overcoming critical challenges in prevention of cardiovascular disease and dementia.
... In the band stop function of the LabVIEW, the cut-off frequencies were selected as 49 Hz and 51 Hz as low and high cut-off values. Therefore the 50 Hz power line noise was subtracted from the signal [14]. ...
It is well-known that in case of cardiovascular diseases an early diagnosis is one of the vital role to prevent the deaths. Although there are many devices and applications to diagnose the diseases, most of them are either too expensive or an expert is required to use it. The aim of the current study is measuring the Electrocardiogram (ECG) signals from the human-body in real-time, processing these signals simultaneously via LabVIEW and by calculating heart rate of a patient using Teager Energy method, detecting tachycardia and bradycardia arrhythmias. Therefore, using an Arduino UNO and SIM800L GSM module, the information of a patient regarding abnormality of his/her heart beats could be sent to a his/her relative or a doctor. With this new low cost and simple application, an arrhythmia could be immediately detected and one can intervene the patient on time.
... While manual and automatic approaches have their strengths and weaknesses, we have chosen fully automatic P-wave processing in order to eliminate the risk of subjectivity in assessment of PWD and, perhaps more importantly, its morphology and identification of terminal-negative component in the inferior leads and lead V1. As we have shown previously [41], the use of signal amplification may consistently result in longer PWD values, thus contributing to a greater prevalence of IAB in some studies that used manual measurements [6,36] but not fully explaining the greater prevalence of biphasic P-wave morphology in inferior leads required for aIAB definition. By adhering to the commercially available automatic ECG processing software, we also aimed to obtain results that can be reproduced by others and applied on a large scale [4]. ...
Background:
Interatrial block (IAB) and abnormal P-wave terminal force in lead V1 (PTFV1) are electrocardiographic (ECG) abnormalities that have been shown to be associated with new-onset atrial fibrillation (AF) and death. However, their prognostic importance has not been proven in cardiac resynchronization therapy (CRT) recipients.
Objective:
To assess if IAB and abnormal PTFV1 are associated with new-onset AF or death in CRT recipients.
Methods:
CRT recipients with sinus rhythm ECG at CRT implantation and no AF history were included (n = 210). Automated analysis of P-wave duration (PWD) and morphology classified patients as having either no IAB (PWD <120 ms), partial IAB (pIAB: PWD ≥120 ms, positive P waves in leads II and aVF), or advanced IAB (aIAB: PWD ≥120 ms and biphasic or negative P wave in leads II or aVF). PTFV1 >0.04 mm•s was considered abnormal. Adjusted Cox regression analyses were performed to assess the impact of IAB and abnormal PTFV1 on the primary endpoint new-onset AF, death, or heart transplant (HTx) and the secondary endpoint death or HTx at 5 years of follow-up.
Results:
IAB was found in 45% of all patients and independently predicted the primary endpoint with HR 1.9 (95% CI 1.2-2.9, p = 0.004) and the secondary endpoint with HR 2.1 (95% CI 1.2-3.4, p = 0.006). Abnormal PTFV1 was not associated with the endpoints.
Conclusions:
IAB is associated with new-onset AF and death in CRT recipients and may be helpful in the risk stratification in the context of heart failure management. Abnormal PTFV1 did not demonstrate any prognostic value.
... During the initial digital ECG measurements, the orthogonal P-wave morphology was registered manually, or in case of low signal quality, borderline morphology, or fluctuating morphology filed for a more detailed assessment to be performed later. After the initial measurements, an automated algorithm developed by J.C., F.H., and P.G.P. was used to automatically assess the orthogonal P-wave morphology from the digital median beats calculated from tracings of leads X, Y, and Z. 19 After this phase, the ECGs in which the orthogonal P-wave morphology was not initially classified, or was classified differently by the user and the algorithm were checked, the probable reason for this discordance was documented, and the final P-wave morphology was decided. In borderline cases between P-wave types the algorithm was generally trusted. ...
Aims:
Identifying subjects at high and low risk of atrial fibrillation (AF) is of interest. This study aims to assess the risk of AF associated with electrocardiographic (ECG) markers linked to atrial fibrosis: P-wave prolongation, 3rd-degree interatrial block, P-terminal force in lead V1, and orthogonal P-wave morphology.
Methods and results:
P-wave parameters were assessed in a representative Finnish population sample aged ≥30 years (n = 7217, 46.0% male, mean age 51.4 years). Subjects (n = 5489) with a readable ECG including the orthogonal leads, sinus rhythm, and a predefined orthogonal P-wave morphology type [positive in leads X and Y and either negative (Type 1) or ± biphasic (Type 2) in lead Z; Type 3 defined as positive in lead X and ± biphasic in lead Y], were followed 10 years from the baseline examinations (performed 1978-80). Subjects discharged with AF diagnosis after any-cause hospitalization (n = 124) were defined as having developed AF. Third-degree interatrial block was defined as P-wave ≥120 ms and the presence of ≥2 ± biphasic P waves in the inferior leads. Hazard ratios (HRs) and confidence intervals (CIs) were assessed with Cox models. Third-degree interatrial block (n = 103, HR 3.18, 95% CI 1.66-6.13; P = 0.001) and Type 3 morphology (n = 216, HR 3.01, 95% CI 1.66-5.45; P < 0.001) were independently associated with the risk of hospitalization with AF. Subjects with P-wave <110 ms and Type 1 morphology (n = 2074) were at low risk (HR 0.46, 95% CI 0.26-0.83; P = 0.006), compared to the rest of the subjects.
Conclusion:
P-wave parameters associate with the risk of hospitalization with AF.
... The first filter used for the ECG signal is the band-stop filter. A 4 th order band-stop Butterworth filter is used with a low cutoff frequency of 47 Hz and a high cut-off frequency of 53 Hz in order to eliminate the powerline interference [7] and the electromyography (EMG) noises. Since the heart rate detection range is between 0.67 Hz and 40 Hz [8] and one of the purposes of this article is to detect the heart rate from the ECG signal, a second filter, which is a 4 th order Butterworth band-pass filter, is used with a low cut-off frequency of 0.67 Hz and a high cut-off frequency of 40 Hz. ...
Sphygmomanometers are conventionally used for measuring blood pressure, namely systolic and diastolic pressures. While measuring the maximum output pressure of the heart, namely systolic, the blood flow is cut with the pressure exerted by the cuff, which may discomfort the patient. To avoid this discomfort, we propose a contactless and cuffless blood pressure measurement system (CBPS) of estimating the blood pressure using non-contact capacitively coupled ECG electrodes and a commercial pulse sensor together with an analog signal acquisition circuitry and a LabVIEW program which calculates the systolic and diastolic pressures from the pulse transit time (PTT). Moreover, non-contact ECG electrodes do not need conductive gel, and the CBPS provides almost instant BP results. These features of the CBPS enable continuous recording of the blood pressure together with the ECG signals in a holter device utilizing contactless electrodes.
... The beginning and end of the P-wave were manually defined. The method has been described in more detail elsewhere [12]. The signalaveraged P-waves were classified as one of four types or "atypical" (Fig. 1) [2,12]. ...
... The method has been described in more detail elsewhere [12]. The signalaveraged P-waves were classified as one of four types or "atypical" (Fig. 1) [2,12]. ...
Background
It has previously been shown that the morphology of the P-wave neither depends on atrial size in healthy subjects with physiologically enlarged atria nor on the physiological anatomical variation in transverse orientation of the left atrium. The present study aimed to investigate if different pressures in the left and right atrium are associated with different P-wave morphologies.
Methods
38 patients with isolated, increased left atrial pressure, 51 patients with isolated, increased right atrial pressure and 76 patients with biatrially increased pressure were studied. All had undergone right heart catheterization and had 12-lead electrocardiographic recordings, which were transformed into vectorcardiograms for detailed P-wave morphology analysis.
Results
Normal P-wave morphology (type 1) was more common in patients with isolated increased pressure in the right atrium while abnormal P-wave morphology (type 2) was more common in the groups with increased left atrial pressure (P = 0.032). Moreover, patients with increased left atrial pressure, either isolated or in conjunction with increased right atrial pressure, had significantly more often a P-wave morphology with a positive deflection in the sagittal plane (P = 0.004).
Conclusion
Isolated elevated right atrial pressure was associated with normal P-wave morphology while left-sided atrial pressure elevation, either isolated or in combination with right atrial pressure elevation, was associated with abnormal P-wave morphology.
... Band-stop filter is a series combination of high and low-pass filter. This type of filter eliminates the noise which lies in the specific range such as 50 Hz power line interference [10]. Notch filter is a special type of band-stop filter that eliminates power line noise. ...
This study is based on measuring the Electrocardiogram (ECG) signals from the human body in real-time with the help of the software called NI LabVIEW. Not only the raw ECG signals, the digital filtered version of the ECG signals can also be displayed in real-time by processing the signals using the digital filtering tools of the program. The ECG itself provides various diagnostic information and NI LabVIEW biomedical toolkit offers many tools that helps to process the signals and perform feature extraction. Thus, this software was preferred for the ECG data acquisition. In this project, heart rate of a patient is calculated by detecting R-R intervals on the ECG tracing using the method called Teager Energy. In order to test the system, several experiments have been conducted with 12 subjects (6 non-smokers + 6 smokers). Their ECG signals were taken in relaxed and after running conditions. The experimental results were recorded for the graphical and statistical analysis. According to the results, the effect of smoking to the heart rate was discussed.
... Cardiac resynchronization therapy (CRT) has been shown to improve left atrial function, however its effect on reverse electrical remodeling has not been properly evaluated [1][2][3][4][5][6]. Atrial electrical remodeling has been a growing area of interest since it was initially described [7,8]. ...
Purpose:
Cardiac resynchronization therapy (CRT) has been shown to improve left atrial function; however the effect on reverse electrical remodeling has been poorly evaluated. We hypothesized that CRT might induce reverse atrial electrical remodeling manifesting in the surface ECG as a shortening in P-wave duration.
Methods:
Patients with CRT and more than 92% biventricular pacing at minimum follow-up of 1 year were included in the analysis. Those with prior history of atrial fibrillation (AF) were excluded. Data were recorded for clinical, echocardiographic and ECG variables prior to implant and at least 12 months post implantation. Semiautomatic calipers and scanned ECGs at 300 DPI maximized × 8 were used to measure P-wave duration and diagnose advanced interatrial block (aIAB) during sinus rhythm. The occurrence of AF was assessed through analyses of intracardiac electrograms and clinical presentations.
Results:
41 patients were included in the study with mean age of 67.4 ±9.6 years, 71% were male, left atrial diameter 41.1 ± 8.5 mm and LV EF 28.5 ± 6.5%. Over a mean follow up of 55 months, a significant reduction in P-wave duration (142.7 ms vs. 133.1 ms; p < 0.001) was noted. The presence of aIAB was significantly reduced (36% vs. 17%; p = 0.03). The incidence of new onset AF was 36%. Time to AF onset after CRT implantation was not influenced by a reduction in P-wave duration.
Conclusion:
CRT induces atrial reverse electrical remodeling manifested as a reduction in P-wave duration. Larger studies are needed to determine the impact on AF incidence after CRT implantation.
... Nevertheless, due to the ill-posed nature of the inverse problem, the reconstruction is susceptible to sources of error, such as the electrode locations, far-field activity, signal amplitudes, and even the minor sources of error that are present in the single beat approach (SB): patient movements modifying waveform body surface electrocardiograms (ECGs) or surrounding noise hiding low amplitude signals. To reduce these errors, signal averaging (SA) methods have been developed and evaluated for arrhythmia diagnosis [5] but not for ECGi. ...
Current clinical electrocardiographic imaging (ECGi) aims to reconstruct epicardial signals using a single selected beat. However, minor sources of error that can be present on a beat-to-beat basis may affect the result, complicating arrhythmia mechanism identification and thus diagnosis and treatment. In this study, we applied signal averaging (SA) to ECGi on atrial and ventricular tachycardia diagnosis compared to a single beat approach. For that, a multi-lead SA algorithm was applied to QRS-complexes or atrial activity to obtain a robust template. Datasets came from patients with confirmed tachycardia obtained by invasive diagnosis. The non-invasive diagnosis was compared to the invasive with activation time maps and other clinical features in order to evaluate the contribution of SA versus the single beat approach (SB). The outcomes indicate that signal averaging improves the quality of non-invasive diagnosis for tachycardia reducing the diagnosis variability and the cycle length error (from 28% with SB to 13% with SA).
... Three different orthogonal P-wave morphologies have previously been characterized, suggested to represent different atrial depolarization paths (Holmqvist et al., 2008). Type 1: predominantly positive leads X and Y and predominantly negative lead Z, type 2: predominantly positive leads X and Y and biphasic lead Z (negative, positive), and type 3: predominantly positive lead X and biphasic leads Y (positive, negative) and Z (negative, positive) (Holmqvist, Platonov, Havmöller, & Carlson, 2007). Although it is plausible that other factors, such as morphological characteristics of the atria, affect P-wave morphology, our group has previously demonstrated that the distribution of P-wave morphologies in healthy athletes does not depend on the size of the atria (Petersson et al., 2014). ...
Background:
It has previously been demonstrated that orthogonal P-wave morphology in healthy athletes does not depend on atrial size, but the possible impact of left atrial orientation on P-wave morphology remains unknown. In this study, we investigated if left atrial transverse orientation affects P-wave morphology in different populations.
Methods:
Forty-seven patients with atrial fibrillation, 21 patients with arrhythmogenic right ventricular cardiomyopathy, 67 healthy athletes, and 56 healthy volunteers were included. All underwent cardiac magnetic resonance imaging or computed tomography and the orientation of the left atrium was determined. All had 12-lead electrocardiographic recordings, which were transformed into orthogonal leads and orthogonal P-wave morphology was obtained.
Results:
The median left atrial transverse orientation was 87 (83, 91) degrees (lower and upper quartiles) in the total study population. There was no difference in left atrial transverse orientation between individuals with different orthogonal P-wave morphologies.
Conclusions:
The physiological variation in left atrial orientation was small within as well as between the different populations. There was no difference in left atrial transverse orientation between subjects with type 1 and type 2 P-wave morphology, implying that in this setting the P-wave morphology was more dependent on atrial conduction than orientation.
