New‐onset intrinsic and paced QRS morphology of right bundle branch block pattern after atrioventricular nodal ablation: Longitudinal dissociation or anatomical bifurcation?

We performed left bundle pacing combined with atrioventricular nodal (AVN) ablation in a patient with persistent atrial fibrillation and refractory symptomatic heart failure. The major findings were new‐onset intrinsic and paced QRS morphology of right bundle branch block (RBBB) pattern after AVN ablation which was performed at a more atrial site compared with the pacing site and the paced RBBB pattern could not be corrected regardless of the pacing output. Longitudinal dissociation cannot explain this observation, while anatomical separation could. We also confirm this was proximal left bundle pacing rather than His bundle pacing.     

New criterion to determine left bundle branch capture on the basis of individualized His bundle or right ventricular septal pacing

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左束支区域起搏可改善右束支阻滞的心电图表现

目的:旨在观察左束支区域起搏(LBBAP)纠正右束支阻滞(RBBB)的临床效果及心电图特点.方法:本研究为单中心、前瞻性观察性研究,纳入2018年4月至2019年12月间入院有心室起搏指征,存在基线RBBB图形且QRS波群时限≥120 ms、左心室射血分数>50％并接受LBBAP的患者,分析LBBAP纠正RBBB的临床...     

希浦系统起搏操作和临床分析:单中心经验

目的总结北京大学第一医院前50例希浦系统起搏病例,为初期开展此项技术提供临床借鉴。方法回顾性分析2019年4-12月本中心同一术者团队行希浦系统起搏操作的前50例患者资料及手术和随访情况。按起搏部位分为希氏束起搏(HBP)组、左束支区域起搏(LBBP)组、室间隔内起搏(IVSP)组,比较各组间的手术操作、起搏结果和参数随访情况。结果按患者手术先后顺序每10例患者一组,共分为5组。随着手术例数的增加,希浦系统起搏的成功率从前10例的50%上升至最后10例的90%,而手术时间显著缩短[(152.7±55.1)min比(89.8±37.7)min,P=0.037],完成20例手术后,成功率稳定在80%以上较好的水平。按照最终起搏的结果,IVSP组15例、HBP组10例、LBBP组25例。左心室激动时间(LVAT),HBP组[(79.4±8.2)ms比(96.0±19.2)ms,P=0.012]和LBBP组[(81.5±13.5)ms比(96.0±19.2)ms,P=0.013]均显著短于IVSP组,差异均有统计学意义;而HBP组和LBBP组[(79.4±8.2)ms比(81.5±13.5)ms,P=0.928]比较,差异无统计学意义。起搏QRS波时限,HBP组[(106.4±19.9)ms比(138.8±18.9)ms,P<0.001]和LBBP组[(118.9±12.3)ms比(138.8±18.9)ms,P<0.001]均显著短于IVSP组,差异均有统计学意义;LBBP组较HBP组延长[(118.9±12.3)ms比(106.4±19.9)ms,P=0.030],差异有统计学意义。但HBP组的起搏阈值显著高于IVSP组[(1.4±0.5)V比(0.6±0.3)V,P<0.001]和LBBP组[(1.4±0.5)V比(0.7±0.2)V,P=0.019],差异均有统计学意义。感知R波则HBP组显著低于IVSP组[(5.7±2.1)mV比(10.2±5.3)mV,P=0.009]和LBBP组[(5.7±2.1)mV比(9.6±2.2)mV,P<0.001]。而LBBP组和IVSP组各项起搏参数均无差异。各组随访期间,起搏阈值和感知R波均无明显变化。手术操作中我们采用了影像法辅助希氏束及左束支区域的解剖定位。结论本中心回顾分析显示,第20~50例的手术操作,可以较熟练掌握希浦系统起搏技术。LBBP可作为初期开展希浦系统起搏的首选。影像解剖定位法可简化手术流程,避免对希氏束和传导束的损伤。     

Cardiac troponin release following left bundle branch pacing

Left bundle branch pacing (LBBP) has emerged as an alternative to His bundle pacing (HBP) to achieve physiologic ventricular stimulation. The extent of myocardial injury during permanent LBBP implantation is currently not known. The aim of the study was to prospectively assess the extent of myocardial injury during LBBP implantation. Cardiac troponin (cTn) levels were measured at baseline and 6–12 h following permanent LBBP. The number of attempts to achieve LBBP was documented. Troponin levels were measured in a control population undergoing other electrophysiology procedures including HBP, other devices involving right ventricular (RV) pacing, radiofrequency ablation for atrial fibrillation (AF) and supraventricular tachycardia (SVT). Significant elevation of troponin (SET) was defined as threefold increase above the upper reference limit (URL) for cTn. Between December 2019 and April 2020, 204 were prospectively enrolled: LBBP in 98 and Control group 106 (SVT, 55; AF, 20; HBP, 17; other devices, 14). SET (>3× URL) was seen in 49.4% of patients in the LBBP group compared to 58.4% in the control group (p = .23). Peak troponin levels were greater in the control group compared to the LBBP group (230.3 ± 320.1 vs. 87.4 ± 71.3 pg/ml; p = .0001). Compared to LBBP (49.4%), SET was observed less frequently following HBP (17.5%; p = .01), and other device implantation (29%; p = .15). Patients requiring >2 attempts (n = 33) had significantly higher incidence of SET compared to <2 attempts (n = 56; 66.7% vs. 39.3%; p = .01). LBBP implantation is associated with myocardial injury. Asymptomatic troponin release following LBBP is less than or comparable to other interventional electrophysiology procedures.     

左束支区域起搏的现状和展望

希氏束和左束支区域的生理性起搏较右室心尖部起搏明显改善心脏的电机械同步性,改善心功能。希氏束起搏是最生理的起搏方式,而且可纠正大部分的完全性左束支传导阻滞,改善心脏再同步化,但也存在起搏阈值高、R波振幅低和潜在的希氏束远端病变风险。左束支呈扇形分布左室间隔内膜面下,起搏阈值和R波振幅同右室心尖部相似,而且左束支近端起搏可纠正病变于希氏束的左束支传导阻滞,可作为心脏再同步化治疗的备选方案。现就左束支的解剖、左束支区域起搏的电生理特点和左束支区域起搏的临床应用进行综述。     

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.     

Loss of Left Bundle Branch Block following Biventricular Pacing Therapy for Heart Failure: Evidence for Electrical Remodeling?

Cardiac resynchronization therapy has been proven to improve symptoms and indices of left ventricular function in patients with heart failure and intraventricular conduction delays. We present a case of a patient with New York Association Class III heart failure and left bundle branch block, who received a biventricular pacemaker in order to achieve cardiac resynchronization. Her symptoms improved markedly, as did left ventricular ejection fraction and dimensions. In addition, her intrinsic QRS duration normalized. This may represent a salutory effect of biventricular pacing on electrical remodeling.     

Right bundle branch pacing: Criteria,characteristics, and outcomes

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