Cardiac resynchronization performed by LBBaP-CRT in patients with cardiac insufficiency and left bundle branch block

Objective

To evaluate the efficacy and safety of left bundle branch area pacing (LBBaP) in patients with heart failure and left bundle branch block (LBBB), and to compare the clinical effects with traditional cardiac resynchronization therapy (CRT).

Methods

Thirty-two patients with dilated cardiomyopathy complicated by cardiac insufficiency and left bundle branch block were divided into CRT group and LBBaP group. Parameters including pacing threshold, R-wave amplitude, pacing impedance and operation time, and X-ray exposure time were recorded. The left ventricular ejection fraction (LVEF), left ventricular end-diastolic diameter (LVEDD), and left ventricular end-systolic diameter (LVESD) were examined by echocardiography. The changes of QRS complex before and after operation were compared.

Results

Compared with CRT group, the LBBaP group spent less time on total operation time and X-ray exposure time and had stable electrode parameters including pacing threshold, R-wave amplitude, and lead impedance after 12-month follow-up. In addition, LBBaP can achieve narrow QRS complex (117.15 ± 9.91) ms immediately than that in CRT group (130.32 ± 12.41) ms. The change of QRS between LBBaP is (50.30 ± 23.79) ms and CRT group is (33.15 ± 20.22) ms. After 6 months' follow-up in LBBaP group, EF was higher than that before operation. Followed up for 12 months after operation, EF and LVEDD in LBBaP group were significantly improved compared with those before operation.

Conclusion

Left bundle branch area pacing is a safe and effective resynchronization method for patients with cardiac insufficiency and asynchronization, which can achieve same clinical effects to CRT.

     

Cardiac resynchronization performed by LBBaP‐CRT in patients with cardiac insufficiency and left bundle branch block

ObjectiveTo evaluate the efficacy and safety of left bundle branch area pacing (LBBaP) in patients with heart failure and left bundle branch block (LBBB), and to compare the clinical effects with traditional cardiac resynchronization therapy (CRT).MethodsThirty‐two patients with dilated cardiomyopathy complicated by cardiac insufficiency and left bundle branch block were divided into CRT group and LBBaP group. Parameters including pacing threshold, R‐wave amplitude, pacing impedance and operation time, and X‐ray exposure time were recorded. The left ventricular ejection fraction (LVEF), left ventricular end‐diastolic diameter (LVEDD), and left ventricular end‐systolic diameter (LVESD) were examined by echocardiography. The changes of QRS complex before and after operation were compared.ResultsCompared with CRT group, the LBBaP group spent less time on total operation time and X‐ray exposure time and had stable electrode parameters including pacing threshold, R‐wave amplitude, and lead impedance after 12‐month follow‐up. In addition, LBBaP can achieve narrow QRS complex (117.15 ± 9.91) ms immediately than that in CRT group (130.32 ± 12.41) ms. The change of QRS between LBBaP is (50.30 ± 23.79) ms and CRT group is (33.15 ± 20.22) ms. After 6 months'' follow‐up in LBBaP group, EF was higher than that before operation. Followed up for 12 months after operation, EF and LVEDD in LBBaP group were significantly improved compared with those before operation.ConclusionLeft bundle branch area pacing is a safe and effective resynchronization method for patients with cardiac insufficiency and asynchronization, which can achieve same clinical effects to CRT.     

Clinical efficacy and predictor of cardiac resynchronization therapy on left bundle branch block-associated heart dysfunction

Background Left bundle branch block （LBBB） results in an altered pattern of left ventricular （LV） activation and subsequent contraction. Cardiac synchrony and cardiac function are deteriorated by LBBB. However, the effect of LBBB history on progressive heart dysfunction and clinical efficacy of cardiac resynchronization therapy （CRT） in such patients are not clear. In this study we explore the clinical efficacy and predictor of cardiac resynchronization therapy in LBBB heart dysfunction. Methods Twenty-seven LBBB patients with severe heart failure were treated with CRT. Twenty-six LBBB patients without CRT served as control. During 6 months follow-up, ECG, plasma NT-proBNP and echocardiogram indexes were measured. Results Compared with baseline, NYHA functional class of 23 patients （85.2%） was improved in CRT group. Compared with baseline and control, QRS duration （QRSd） was significantly more narrow （P = 0.023, P = 0.019）, NT-proBNP was significantly lower （P = 0.011,P = 0.009）, ventricular septal to left ventricular posterior wall delay time and left ventricular dyssynchrony index （Ts-SD） were significantly worse （P 〈 0.05）; left ventricular ejection fraction, left ventricular end-systolic volume, mitral regurgitation area were significantly improved in CRT group （P 〈 0.05）. when the LBBB history was I〉 2 years and QRSd I〉 155 ms, the sensitivity and specificity of CRT super-response were 53.4% and 85.6% respectively. Conclusions CRT can improve the synchronization and hemodynamic of LBBB patients with heart dysfunction, the LBBB history I〉 2 years and QRSd I〉 155 ms are one of the CRT super-response predictors.     

The benefit of cardiac resynchronization therapy and QRS duration: a meta-analysis

CRT and QRS Duration . Background: Cardiac resynchronization therapy (CRT) improves outcomes in patients with heart failure (HF) because of reduced left ventricular systolic function and a wide QRS complex. Whether this benefit is consistent across all degrees of QRS widening is unclear. We performed a meta‐analysis of randomized clinical trials to evaluate the impact of QRS duration on the efficacy of CRT. Methods and Results: We searched MEDLINE and EMBASE databases for studies evaluating the efficacy of CRT in patients with HF. Only trials that reported subgroup data according to QRS duration were included. Hazard ratios (HR) with 95% confidence interval (CI) were calculated using a random effects model. Five trials involving 6,501 patients (4,437 with QRS ≥ 150 ms and 2,064 with QRS < 150 ms) were included. Three trials, enrolling patients with mild to moderate HF, compared CRT‐implantable cardioverter defibrillator with CRT, whereas CRT versus medical therapy was compared in the other 2 trials, which included patients with advanced HF. Based on the pooled estimate across the 5 studies, CRT significantly decreased the primary endpoint of death or hospitalization for HF in patients with QRS ≥ 150 ms (HR = 0.58, 95% CI: 0.50–0.68; P < 0.00001), but not in patients with QRS < 150 ms (HR = 0.95, 95% CI: 0.83–1.10; P = 0.51). These results were consistent across all degrees of HF severity. Conclusions: The benefit of CRT seems to be dependent on QRS duration. Available data suggest a significant benefit associated with CRT in patients with QRS ≥ 150 ms, but not in patients with QRS < 150 ms. Further studies are needed to identify patients with QRS < 150 ms who might benefit from CRT. (J Cardiovasc Electrophysiol, Vol. 23, pp. 163‐168, February 2012)     

Remarkable response to cardiac resynchronization therapy via left bundle branch pacing in patients with true left bundle branch block

BackgroundLeft bundle branch pacing (LBBP) has been suggested as an alternative means to deliver cardiac resynchronization therapy (CRT).HypothesisLBBP may deliver resynchronization therapy along with an advantage over traditional biventricular (BiV) pacing in clinical outcomes.MethodsHeart failure patients who presented LBBB morphology according to Strauss''s criteria and received successful CRT procedure were enrolled in the present study. Propensity score matching was applied to match patients into LBBP‐CRT group and BiV‐CRT group. Then, the electrographic data, the echocardiographic data and New York heart association (NYHA) class were compared between the groups.ResultsTwenty‐one patients with successful LBBP procedure and another 21 matched patients with successful BiV‐CRT procedure were finally enrolled in the study. The QRS duration (QRSd) was narrowed from 167.7 ± 14.9 ms to 111.7 ± 12.3 ms (P < .0001) in the LBBP‐CRT group and from 163.6 ± 13.8 ms to 130.1 ± 14.0 ms (P < .0001) in the BiV‐CRT group. A trend toward better left ventricular ejection fraction (LVEF) was recorded in the LBBP‐CRT group (50.9 ± 10.7% vs 44.4 ± 13.3%, P = .12) compared to that in the BiV‐CRT group at the 6‐month follow‐up. A trend toward better echocardiographic response was documented in patients receiving LBBP‐CRT procedure (90.5% vs 80.9%, P = .43) and more super CRT response was documented in the LBBP‐CRT group (80.9% vs 57.1%, P = .09) compared to that in the BiV‐CRT group.ConclusionsLBBP‐CRT can dramatically improve the electrical synchrony in heart failure patients with LBBB. Meanwhile, compared with the traditional BiV‐CRT, it has a tendency to significantly improve LVEF and enhance the NYHA cardiac function scores.     

Comparison of four LBBB definitions for predicting mortality in patients receiving cardiac resynchronization therapy

Background

Left bundle branch block (LBBB) is considered an important prognostic parameter in cardiac resynchronization therapy (CRT). We aimed to evaluate, in a sizeable cohort of patients with CRT, long‐term mortality, and morbidity according to four different electrocardiographic definitions of LBBB.

Methods

This longitudinal cohort study included consecutive patients who underwent CRT device implantation in our institution in years 2006–2014. Two endpoints were assessed: (a) death from any cause or urgent heart transplantation, and (b) death from any cause or heart failure admission. All preimplantation ECGs were analyzed by three physicians blinded to outcome and categorized as LBBB or non‐LBBB according to four definitions.

Results

A total of 552 CRT patients entered survival analysis. According to the conventional definition, 350 (63.4%) patients had LBBB, and the Marriott, WHO/AHA, and Strauss definitions identified LBBB in 254 (46.0%), 218 (39.5%) and 226 (40.9%) patients, respectively. During the 9 years of observation, 232 patients died, the combined endpoint was met by 292 patients. The Strauss LBBB definition was significantly better to the other definitions in predicting survival (Kaplan–Meier analysis with comparison of C‐statistics). Multivariate Cox regression model showed that LBBB was the major determinant of all‐cause mortality with the Strauss definition having the lowest hazard ratio (0.51) of the four studied definitions.

Conclusions

Criteria included in various definitions of LBBB result in a diagnosis of LBBB in divergent groups of patients. Differences in LBBB definitions have clinical consequences, as patients without ‘complete/true’ LBBB probably get no mortality benefit from CRT.

     

真性完全性左束支阻滞与心脏再同步化治疗超反应的研究进展

真性完全性左束支阻滞作为一个新概念被提出,不仅促进了心电学的发展,而且也丰富了心脏再同步化治疗心力衰竭的内容,并成为慢性心力衰竭伴真性完全性左束支阻滞的患者对心脏再同步化治疗获超反应的一个新的预测因子.     

Recurrent acute pulmonary oedema and cardiac arrest secondary to intermittent electrical dyssynchrony: a role for cardiac resynchronization despite preserved left ventricular function

Recurrent pulmonary oedema with no obvious precipitant can prove difficult to treat in patients with preserved left ventricular (LV) systolic function. This report describes the novel use of cardiac resynchronization therapy (CRT) in the prevention of acute pulmonary oedema precipitated by intermittent electrical dyssynchrony in a patient with preserved LV systolic function.     

Comparison of the relation of the ESC 2021 and ESC 2013 definitions of left bundle branch block with clinical and echocardiographic outcome in cardiac resynchronization therapy

Introduction

We aimed to investigate the impact of the 2021 European Society of Cardiology (ESC) guideline changes in left bundle branch block (LBBB) definition on cardiac resynchronization therapy (CRT) patient selection and outcomes.

Methods

The MUG (Maastricht, Utrecht, Groningen) registry, consisting of consecutive patients implanted with a CRT device between 2001 and 2015 was studied. For this study, patients with baseline sinus rhythm and QRS duration ≥ 130ms were eligible. Patients were classified according to ESC 2013 and 2021 guideline LBBB definitions and QRS duration. Endpoints were heart transplantation, LVAD implantation or mortality (HTx/LVAD/mortality) and echocardiographic response (LVESV reduction ≥15%).

Results

The analyses included 1.202, typical CRT patients. The ESC 2021 definition resulted in considerably less LBBB diagnoses compared to the 2013 definition (31.6% vs. 80.9%, respectively). Applying the 2013 definition resulted in significant separation of the Kaplan–Meier curves of HTx/LVAD/mortality (p < .0001). A significantly higher echocardiographic response rate was found in the LBBB compared to the non-LBBB group using the 2013 definition. These differences in HTx/LVAD/mortality and echocardiographic response were not found when applying the 2021 definition.

Conclusion

The ESC 2021 LBBB definition leads to a considerably lower percentage of patients with baseline LBBB then the ESC 2013 definition. This does not lead to better differentiation of CRT responders, nor does this lead to a stronger association with clinical outcomes after CRT. In fact, stratification according to the 2021 definition is not associated with a difference in clinical or echocardiographic outcome, implying that the guideline changes may negatively influence CRT implantation practice with a weakened recommendation in patients that will benefit from CRT.     

Electrocardiography of cardiac resynchronization therapy: Pitfalls and practical tips

Cardiac resynchronization therapy (CRT) has been established as an effective mode of therapy in patients with heart failure and concurrent cardiac dyssynchrony, principally in the form of left bundle branch block (LBBB). The widespread use of CRT has ushered in a new landscape in 12-lead electrocardiography (ECG). ECG readings in these patients are most important to guide troubleshooting and also appropriate device programming, as well as discerning and managing nonresponders. A set of four ECG recordings need to accompany each patient with a CRT device, including a baseline ECG and recordings from monochamber (right and left ventricular) and biventricular pacing, which can be compared against a new recording to facilitate the evaluation of proper versus problematic biventricular pacing. Precordial ECG leads V1/2 acquired at the fourth intercostal space and limb leads, I and III, together with a quick assessment of perpendicular leads I and aVF to determine the quadrant of the QRS axis in the hexaxial diagram, may provide the framework for proper ECG interpretation in these patients. This important issue of 12-lead ECG in CRT patients is herein reviewed, pitfalls are pointed out and practical tips are provided for ECG reading to help recognize and manage problems with CRT device function. Furthermore, several pertinent ECG recordings and tabulated data are provided, and an algorithm is suggested that integrates prior algorithms and relevant information from current literature.     

Physiologic resynchronization therapy: a case of his bundle pacing reversing physiologic conduction in a patient with CHF and LBBB during 2 years of observation

This is a case of a patient with congestive heart failure and left bundle branch block who was referred for cardiac resynchronization therapy implantation. Instead, a His bundle pacing was achieved with a narrow QRS complex. During 27 months of observation, the patient improved dramatically from NYHA class IV to I. Echo parameters improved significantly the LV diameter from 75/50 to 60/40 mm, EF from 28 to 50%, and mitral regurgitation from 4 to 2°.     

Recovery of complete left bundle branch block following heart failure improvement by left bundle branch pacing in a patient

A 57‐year‐old male presented with symptomatic systolic heart failure and complete left bundle branch block (LBBB). Left bundle branch pacing corrected LBBB at a low capture threshold (0.5V @0.4ms) with right bundle branch conduction delay and paced QRS morphology changed to near‐normal by adjusting AV delay with diminished RBBD. At 1‐year follow‐up, the patient had a significant improvement in heart failure and LBBB automatically resolved with a rate‐dependent pattern. LBBP may be an alternative to conventional cardiac resynchronization therapy with the likelihood of recovery of LBBB. More research is needed to evaluate the potential use of this pacing strategy in patients with LBBB and heart failure.     

Cardiac resynchronization therapy and ventricular tachyarrhythmia burden

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左束支阻滞性心肌病

长期的真性左束支阻滞可引起左室扩大、心功能进行性下降,进而发展为伴有心功能不全的心肌病。这种左束支阻滞性心肌病的发病机制尚不明确,可能与左束支阻滞所致的电-机械活动失同步有关。该病的临床诊断过程与获得性心肌病一致,关键是识别真性左束支阻滞。心脏再同步化治疗能有效逆转左束支阻滞性心肌病。     

右束支阻滞患者心脏再同步治疗疗效分析

目的 回顾分析阜外心血管病医院心律失常中心合并右束支阻滞(RBBB)的心力衰竭患者心脏再同步治疗(CRT)疗效.方法 本中心自2008年1月至2010年12月植入CRT-P/D的合并RBBB的心力衰竭患者,接受常规每3～6个月门诊随访,随访内容包括心功能(NYHA分级)、6 min步行距离、Minnesota生活质量评分、超声心动图及程控等指标.结果 共7例合并RBBB心力衰竭患者植入CRT-P/D,其中男6例,女1例,年龄19 ～74(57±19)岁.随访0.3～43.0(17.6±16.7)个月.随访期间发生心力衰竭住院事件7次,3例患者因心力衰竭加重死亡.6例患者为CRT无反应者,1例为CRT反应者.结论 合并RBBB的心力衰竭患者CRT无明显获益.