Figure 3 - uploaded by David Zizek
Content may be subject to copyright.
Myocardial perfusion images of regional viable (A) and non-viable myocardium (B) at the postero-lateral LV lead position in the standard 20-segment model.
Source publication
The presence of myocardial fibrosis is associated with ventricular tachyarrhythmia (VT) occurrence irrespective of cardiomyopathy etiology. The aim of our study was to evaluate the impact of global and regional viability on VTs in patients undergoing cardiac resynchronization therapy (CRT).
Fifty-seven patients with advanced heart failure (age 62.3...
Context in source publication
Context 1
... without VTs had more viable segments (17.6 ± 2.35 vs 14.2 ± 4.0; P = .002) and higher via- bility of the corresponding segments at LV lead position (66.1% ± 10.3% vs 54.8% ± 11.4% of tracer activity; P = .001). Distribution of non-viable segments (tracer uptake \ 50% of normal myocardium) according to 20- segments model is presented in Table 1. In VTs group, more patients had non-viable segments in antero-lateral, infero-lateral, inferior and also in apical region of LV. In addition, the example of two patients with viable and non-viable segments in the LV pacing lead area was also noted in Figure 3. All segments at the LV lead were viable in only two patients (11.1%) with registered VTs and in 26 patients (66.7%) without VTs (P \ .001). In addition, among patients with registered VTs, the extent of regional viability is also related to the number of malignant tachyarrhythmias. Patients with more than two appropriate device therapies had lower regional viability [52.3% (46.5-54.5) vs 66.5% (55.0-68.0); P = .013]. VTs, Ventricular tachyarrhythmias; CRT, cardiac resynchronization therapy; NYHA class, New York Heart Association class; CABG, coronary artery bypass grafting; PCI, percutaneous coronary intervention; MPI, myocardial perfusion imaging; LVEF, left ventricular ejection fraction; LVESV, left ventricular end systolic volume; LVEDV, left ventricular end diastolic volume; 6-MWT, 6-minute walking distance test; BNP, brain natriuretic peptide; AF, atrial fibrillation; LV, left ventricle; ACE-i, angiotensin-converting enzyme inhibitors; ARB, angiotensin II receptor blockers; VAD, ventricular assist device. * Location of non-viable segments (tracer uptake \ 50% of normal myocardium) according to 20-segment model (Figure 2): segments 1, 7, 13 presented anterior; segments 6, 12, 18 antero-lateral; segments 5, 11, 17 infero-lateral; segments 4, 10, 16 inferior; segments 3, 9, 15 infero-septal; segments 2, 8, 14 antero-septal part of the left ventricle and segments 19, 20 were ...
Similar publications
Background
Ventricular lead implantation is relatively difficult for patients with bradyarrhythmia after tricuspid valve replacement. Right atrial (RA) abnormalities often occurred in patients with tricuspid valve disease; conventional coronary sinus (CS) lead implantation is not easy to operate. Therefore, it is necessary to develop a safe method...
Background:
Endocardial cardiac resynchronization therapy (eCRT) avoids the limitations and failures of coronary sinus (CS) resynchronization. However, data regarding long-term outcomes are lacking.
Objective:
The purpose of this study was to report the long-term outcome of eCRT performed using the Jurdham procedure in a real-world setting.
Met...
Aims
Cardiac resynchronization therapy (CRT) upgrades may be less likely to improve following intervention. Leadless left ventricular (LV) endocardial pacing has been used for patients with previously failed CRT or high-risk upgrades. We compared procedural and long-term outcomes in patients undergoing coronary sinus (CS) CRT upgrades with high-ris...
![CMR–ECGi–CTA roadmap reconstruction [25]. Workflow for CMR-ECGI-CTA...](publication/354449968/figure/fig1/AS:1129740735905796@1646362589275/CMR-ECGi-CTA-roadmap-reconstruction-25-Workflow-for-CMR-ECGI-CTA-roadmap_Q320.jpg)
Purpose of Review
Cardiac resynchronization therapy (CRT) represents a well-established and effective non-pharmaceutical heart failure (HF) treatment in selected patients. Still, a significant number of patients remain CRT non-responders. An optimal placement of the left ventricular (LV) lead appears crucial for the intended hemodynamic and hence c...
Background: Biventricular pacing (BiV) has been recently proposed as a new therapy in selected patients with advanced heart failure (CHF). The aim of the study is to describe the clinical outcome in the group of patients treated with BiV pacing in our center. Material and methods: In 11 patients the left ventricular (LV) pacing was achieved via the...
Citations
... In addition to reducing the chances of CRT response, the presence of LV scar has also been implicated in increased arrhythmia risk and ventricular tachycardia (VT) in the CRT population (24). A study of 57 consecutive patients undergoing CRT placement who had SPECT MPI reported that decreased global viability, as well as decreased local viability at the location of the LV lead had increased the risks of post-implantation VT (25). The utility of combining echocardiography with speckle tracking strain and nuclear SPECT imaging was evaluated in a randomized controlled trial of 182 patients (26). ...
Cardiac electrophysiology procedures have evolved to provide improvement in morbidity and mortality for many patients. Cardiac resynchronization therapy (CRT), implantable cardioverter/defibrillator (ICD) placement and lead extraction procedures are proven procedures, associated with significant reductions in patient morbidity and mortality as well as improved quality of life. The applications and optimization of these therapies are an evolving field. The optimal use and outcomes of cardiac electrophysiology procedures require a multidisciplinary approach to patient selection, device selection, and procedural planning. Cardiac imaging using echocardiography plays a key role in selection of patients for CRT therapy, for guidance of left ventricular (LV) lead placement, and for optimization of atrioventricular pacing delays in patients with CRT. Cardiac computed tomography (CT) is an important tool in assessment of lead perforation, as well as assessing risk of lead extraction and procedural planning. Cardiac magnetic resonance imaging (MRI) is an important adjunct to transthoracic echocardiography for patient selection and risk stratification for defibrillator therapy for multiple disease states including ischemic cardiomyopathy, hypertrophic cardiomyopathy, cardiac sarcoidosis, and arrhythmogenic right ventricular cardiomyopathy (ARVC). Cardiac positron emission tomography (PET) is a useful adjunct to the diagnosis of device infections as well as inflammatory conditions including cardiac sarcoidosis. Our review attempts to summarize the contemporary roles of multimodality imaging in CRT therapy, ICD therapy and lead extraction therapy.
... A high LV pacing threshold (PT) at resynchronization device implantation may be a contributing factor to the adverse CRT outcome and could indicate a regional myocardial scar [10]. In addition, our previous study demonstrated that lower regional viability in the vicinity of the LV lead pacing site could be associated with increased risk of malignant tachyarrhythmias [11]. ...
... On the other hand, in a study with ischemic CRT patients, regional scar and reversible ischemia adjacent to LV pacing site were independent predictors of HF hospitalization and death [8]. Furthermore, in our previous study we showed that lower regional LV viability could be associated with increased risk of malignant tachyarrhythmias [11]. In addition, a substudy of MADIT-CRT (multicentre automatic defibrillator implantation trial with cardiac resynchronization therapy) trial demonstrated that patients with anterior LV lead position and prior adjacent myocardial infarction had an increased risk of malignant arrhythmias [20]. ...
... Higher LVPT is an issue of substantial importance, not just in terms of increased battery drain and potentially diminished echocardiographic response [6][7][8]10], but also in view of the current controversy regarding the need of implantable defibrillator backup. Patients with increased scar burden should be considered for CRT-D as they could pose a higher risk of VA occurrence [9,11]. However, localization of scar requires specialized imaging techniques and personnel that may not be promptly available before CRT device implantation. ...
Background
Cardiac resynchronization therapy (CRT) is an established heart failure (HF) treatment option, however its effect on ventricular arrhythmias (VAs) is controversial. Regional scar burden and high left ventricular (LV) pacing threshold (PT) are associated with poor outcome in CRT patients. The aim of our study was to analyze the impact of intraoperative LVPT on VA occurrence.
Methods
Eighty consecutive patients with advanced HF scheduled for a CRT defibrillator device [aged 63.3 ± 10.9 years; New York Heart Association II–III 86.2%; 52 males (65%); 34 ischemic etiology (42.5%); 71 sinus rhythm (88.7%); QRS duration 168 ± 25.7 ms] were evaluated using single-photon emission computed tomography myocardial perfusion imaging. Regional myocardial viability was calculated as the mean tracer activity in the corresponding segments at the LV lead pacing site. Fluoroscopic position and intraoperative LVPT were determined at implant after the final LV lead position was determined.
Results
LVPT was inversely associated with regional myocardial viability (ρ −0.785, p < 0.001). After a median follow-up of 36 months (24–57) months VAs were registered in 27 patients (33.7%). Patients with VAs had higher median intraoperative LVPT compared to those without VAs [2.2 V (1.9–2.8) vs. 0.8 V (0.6–1.2), p < 0.001]. In a multivariate logistic regression model intraoperative LVPT was identified as a strong independent predictor of VAs.
Conclusion
Increased intraoperative LVPT during CRT could be associated with lower regional myocardial viability at LV lead location. CRT patients with higher LVPT could have an increased risk of VA occurrence.
... However, the effect of CRT on arrhythmia susceptibility has not been definitively established and data regarding the risk of ventricular arrhythmias (VA) with CRT has been limited and conflicting. Case reports have provided anecdotal evidence of CRT precipitating ventricular tachycardia [3,4]; moreover the presence of scarred myocardium has been associated with an increased risk of arrhythmia in CRT [5,6]. Multiple mechanisms have been proposed for this phenomenon. ...
... Multiple mechanisms have been proposed for this phenomenon. Epicardial pacing results in a reversal of the normal physiologic myocardial activation sequence, which prolongs the QT interval and produces a substrate and the trigger for reentrant arrhythmias in both canine and human subjects [5,7]. The CRT non-responders also experience an increase in ventricular arrhythmia burden [8]. ...
... Diminishing of intraventricular conduction delay, and prevention of pause-dependent tachyarrhythmias, as seen with CRT, may contribute to this phenomenon as well [18]. All these effects could be dependent on LV location [19] and proximity to the scar [5]. Neither the LV lead position, the pacing polarity nor LV lead sensed voltage (a surrogate of scar proximity) affected the change in VA in our population. ...
... Furthermore, it has been shown to increase the risk for ventricular arrhythmias. 20 Therefore, as computer simulations suggest, the optimal LV lead position should be a compromise between a position distant from the scar and from the septum, 21 while the concept of early activation for potential scar unloading remains to be demonstrated in vivo. ...
Aims:
The interaction between asynchronous regional myocardial activation and left ventricular (LV) wall remodelling has not been well established. We investigated the relationship between time of onset of longitudinal shortening (Tonset), regional myocardial work, and segmental LV wall thickness (SWT) in patients treated with cardiac resynchronization therapy (CRT).
Methods and results:
We analysed 26 patients with sinus rhythm, non-ischaemic cardiomyopathy (63 ± 9 years, 69% male, QRS duration 174 ± 18 ms) and positive response to CRT (15% reduction in end-systolic volume). Longitudinal strain was obtained by 2D speckle-tracking echocardiography before and after [14.5 (7–29) months] CRT. Tonset and SWT were measured in 18 segments per LV. Segmental myocardial work was calculated from non-invasive segmental stress–strain loop area. Before CRT, Tonset was the shortest in septal and anteroseptal and the longest in lateral and posterior walls (P < 0.001) and not different after CRT (P = 0.733). Before CRT, septal and anteroseptal walls were significantly thinner than lateral and posterior. After CRT, reverse remodelling increased thickness in septal and anteroseptal and thinned lateral and posterior segments (P < 0.001). Before CRT, non-uniformity in work distribution with reduced work in septal and anteroseptal and increased work in lateral and posterior walls (P < 0.001) was observed. After CRT, distribution of myocardial work was uniform (P = 0.215).
Conclusion:
Dys-synchronous myocardial shortening is related to thinning of early and thickening of late activated segments in heart failure with conduction delay. Correction of dys-synchrony leads to regression of inhomogeneity towards more evenly distributed wall thickness. Regional differences in myocardial work load that are homogenized by successful CRT are considered as the underlying pathophysiological mechanism.
Heart failure remains a highly prevalent disease with significant morbidity and mortality. Millions of patients are affected worldwide and their treatment is associated with a significant cost for the healthcare systems, especially in developed countries. In approximately two-third of the cases, ischemic heart disease is the cause of the syndrome. Therefore, myocardial perfusion single photon emission computed tomography (SPECT) imaging is a key element in the diagnostic investigation, prognostication, and management of patients with heart failure. Perfusion images are obtained according to various well-established protocols, after the administration of either thallium-201 or technetium-99m labelled radiotracers in combination with several stress techniques. In the future, technological innovations and improvements of reconstruction methods are expected to strengthen the role of myocardial perfusion SPECT imaging as a useful tool for the investigation of heart failure and patient’s management.
The differentiation between infarcted, non-viable myocardium and myocardium that is still viable has been an area of extensive research and debate over several decades. Despite this, controversy still exists as to the definitions of viable myocardium, the best non-invasive imaging method to use for viability assessment and whether viability is clinically important or not. This chapter will define viability in its different forms, compare and contrast the non-invasive imaging modalities most commonly used, and discuss the clinical context where knowledge of viability may inform clinical decisions at a patient level. Areas of ongoing research and emerging new imaging methods will be highlighted and discussed.
