Right Ventricular Electrical and Mechanical Synchronization by Properly Timed Septal Pacing in a Patient with Right Bundle Branch Block and First Degree AV Block—A Case Report

We present a case of near‐normalization of the QRS by septal pacing in a patient with dual‐chamber pacemaker and underlying complete right bundle branch block and first degree atrioventricular block. The right ventricular mechanical synchronization suggested by the ECG was validated as such by strain echo. To the best of our knowledge, this is the first time it has been shown that the narrowing of the QRS corresponds to mechanical synchronization in a case of this seldom‐recognized phenomenon.     

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...     

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.     

普通心室电极导线经心脏静脉行左室起搏的实验研究

探讨普通电极导线经心脏静脉行左室起搏的可行性和牢固性。选用 10个新鲜猪心 ,用 3种形态的普通电极导线 (4翼、2翼和无翼 )分别插入右室心尖部、心大静脉、左室后静脉和心中静脉 ,测电极导线在心脏静脉的深度、阻抗和拔出力量。右室心尖部作为对照组 ,仅测阻抗和拔出力量。结果 :三种普通电极导线都能成功地送入心脏静脉。三种电极导线在同一心脏静脉进入深度之间无差异 (P >0 .0 5 ) ,在不同心脏静脉进入深度之间有显著差异(P <0 .0 5 )。电极导线在所有心脏静脉的拔出力量都大于右室心尖部 (P <0 .0 5 )。三种电极导线在同一心脏静脉拔出力量之间无差异 (P >0 .0 5 ) ;4翼、2翼电极导线在不同心脏静脉拔出力量之间也无差异 (P >0 .0 5 ) ,而无翼电极导线有差异 (P =0 .0 4)。电极导线进入心脏静脉深度与拔出力量之间存在正相关 (r=0 .48,P <0 .0 0 1)。电极导线在心脏静脉的阻抗为 6 35± 32 3Ω。结论 :三种普通心室电极导线都可以送入心脏静脉远端 ,都较牢固     

Upgrading Pacemaker Patients with Right Ventricular Apical Pacing to Right Ventricular Septal Pacing Improves Left Ventricular Performance and Functional Capacity

Background : Right ventricular (RV) apical pacing results in abnormal left ventricular (LV) electrical and mechanical activation and is associated with an increased risk of developing heart failure. Chronic RV septal pacing has been shown to be superior to RV apical pacing in newly implanted patients. However, whether RV septal pacing can reverse deleterious effects of RV apical pacing remain unclear.
Methods : We evaluated the effects of RV septal pacing on LV performance and functional capacity before and at 18 months after device replacement in 12 patients with previously permanent RV apical pacing and in 12 control patients that continued RV apical pacing. All patients underwent radionuclide ventriculography and 6-minute hallwalk (6-MHW) test before replacement (baseline) and at 18 months afterward to determine changes in LV performance and functional capacity, respectively.
Results : After RV septal upgraded, there was a significant decrease in paced QRS duration (171.2 ± 3.9 ms to 160.4 ± 3.5 ms, P = 0.0016), increase in LV ejection fraction (55.2 ± 2.6% vs 60.4 ± 2.9%, P = 0.0002), the peak ventricular filling rate (2.60 ± 0.13 s⁻¹ vs 3.01 ± 0.14 s⁻¹, P = 0.046), and 6-MHW (308.2 ± 31.6 m vs 355.5 ± 34.2 m, P = 0.015) at 18 months compared with baseline. No changes in these parameters were observed in the control group (P > 0.05).
Conclusion : RV septal pacing upgraded improves LV systolic and diastolic function and functional capacity in patients with previously permanent RV apical pacing. These findings suggest that RV septal pacing can reverse the deleterious effects of RV apical pacing in patients who required permanent ventricular pacing.     

右室流出道起搏现状

右室心尖部作为传统的永久心脏起搏器植入位点,主要是因为电极容易放置及电极脱位率低。但是心尖部起搏属非生理性起搏,它使心室除极和机械收缩发生异常,从而导致长期的血流动力学紊乱(心室收缩和舒张异常)和组织结构的改变。随着近年主动固定的螺旋电极及螺旋电极操作手柄的问世,使右室流出道起搏成为可能。大量动物实验和临床研究提示右室流出道靠近房室结、希氏束部位,在此部位起搏心室激动和收缩顺序趋于正常,从而能明显的改善血流动力学指标。目前右室流出道起搏尚处于临床实验阶段,且关于右室流出道解剖位点的确定,适宜患者群的筛选标准、监测和评价指标的选择尚无统一的标准。其长期效果及能否改善患者预后等还有待更深入的研究。现就目前国内外关于右室流出道起搏的研究现状综述如下。     

Left Heart Pacing—Experience with Several Types of Coronary Vein Leads

Our experience with 121 coronary vein (CV) leads in 116 patients shows that CV leads are the leads of choice for pacing the left ventricle (LV). The information gained from pre-operative venous angiography permits individual selection of the most appropriate lead model for each case. The use of steerable electrophysiology catheters facilitates guide catheter cannulation of the coronary sinus (CS) when the anatomy is difficult and reduces the risk of complications. By selecting the CV lead model most suitable for each individual patient, we achieved successful implantation in 99.1% of patients. In this day and age, epicardial electrodes should be restricted to cases with CS anomalies which make CS cannulation impossible, and to LV lead implantation during heart surgery.     

Chronic Effect of Right Ventricular Pacing on Left Ventricular Rotational Synchrony in Patients with Complete Atrioventricular Block

Background: Chronic effect of right ventricular (RV) pacing on left ventricular (LV) rotational synchrony is unknown. The aim of this study is to assess chronic effect of RV pacing on LV rotational synchrony using two‐dimensional ultrasound speckle tracking imaging. Methods and Results: Thirty‐one patients who underwent dual‐chamber pacemaker implantation for complete atrioventricular block, and age‐ and sex‐matched 10 healthy controls were assessed. We divided our patients into RV apical (RVA, n = 16) and RV outflow tract (RVOT, n = 15) pacing groups. We compared echocardiographic parameters such as LV rotational synchrony between pacing groups and healthy control. We defined Q to peak rotation interval as the interval from the beginning of the Q‐wave to the peak apical counter‐clockwise or peak basal clockwise rotation. We calculated apical–basal rotation delay by subtracting basal Q to peak rotation interval from apical one as the representative of rotational synchronization. Apical–basal rotation delay of RVA pacing was significantly longer than that of healthy control (100 ± 110 vs. ?6 ± 15 ms, P = 0.002), while there was no statistically significant difference between RVOT pacing and healthy control (?3 ± 99 vs. ?6 ± 15 ms, P = 0.919). Conclusions: LV rotation during RVOT pacing is synchronous at 15 months after pacemaker implantation, while RVA pacing provokes LV rotational dyssynchrony by inducing delayed apical rotation at 7 years after pacemaker implantation in patients with complete atrioventricular block. (Echocardiography 2011;28:69‐75)     

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。     

双室同步起搏的临床应用及置入左室电极的初步体会

观察双室同步起搏治疗充血性心力衰竭 (CHF)的疗效 ,探讨左室电极置入的方法及注意事项。 10例患者均为原发性扩张型心肌病 (DCM)并CHF ,符合双室同步起搏治疗的指征。其中 8例置入Medtronic 2 187电极 ,1例置入Medtronic 2 188电极 ,1例置入右室主动固定电极。 9例左室电极置入成功 ,1例失败改行右室双部位起搏 ,术后患者左室舒张未径、左室射血分数及 6min步行距离均有改善 (术后 3个月与术前分别比较 :70 .8± 9.5vs 79.5± 12 .5mm ,0 .4 2± 0 .13vs 0 .2 5± 0 .10 ,384 .8± 4 5 .4vs 2 78.6± 34.5m ;P <0 .0 5或 0 .0 1)。借助电生理冠状静脉窦 (CS)标测电极、CS造影 (包括直接逆行CS造影和冠状动脉造影使CS间接显像 )对指导左室电极的置入有较大的价值。结论 :双室同步起搏治疗CHF疗效肯定 ,借助CS标测电极及CS造影可提高左室电极置入的成功率     

普通电极导线行右房左室或双心室起搏的初步临床观察

探讨普通电极导线置入心脏静脉起搏左室的可行性。选择 9例患者为研究对象 ,其中扩张型心肌病 3例、缺血性心脏病 3例、其他 3例 ,均伴不同程度的心力衰竭 ,心功能Ⅱ～Ⅳ级。所有患者都安置DDD起搏器。窦性心律伴房室阻滞 (AVB)或完全性左束支阻滞 (CLBBB)患者 ,行右房左室顺序起搏 ;房颤患者行双心室起搏。左心室起搏是将普通右心室导线 (MedtronicCapSureSP 4 0 2 3)通过冠状窦送入心脏静脉施行的。结果 :7例成功 ,2例失败。导线定位在左室后静脉 1例、后侧静脉 3例、侧静脉 3例。术中测左室起搏阈电压、阻抗和R波振幅分别是 0 .7± 0 .2V、6 2 3± 6 6Ω、10 .1± 6 .0mV。术后 2～ 18个月阈电压、阻抗分别是 0 .5± 0V、5 2 1± 5 1Ω。术后 1～ 2周平均心功能从2 .9级改善到 1.9级 ,平均心胸比值从 0 .6 1缩小到 0 .5 7,平均左室射血分数从 0 .39升至 0 .4 4。随访期未发现左室导线脱位 ,膈肌起搏等并发症。结论 :普通电极导线置入心脏静脉长期起搏左心室是可行的、牢靠的。     

Clinical Outcomes of His Bundle Pacing Compared to Right Ventricular Pacing

Background

Right ventricular pacing (RVP) is associated with heart failure and increased mortality. His bundle pacing (HBP) is a physiological alternative to RVP.

Window to the Heart: The Value of a Native and Paced QRS Duration. Current Perspective and Review

Given the technological advances and reliance upon expensive testing for guiding therapy, it is surprising how an inexpensive, low tech electrocardiogram can provide a wealth of information pertaining to the underlying cardiovascular status of a patient. In this article we review the changes in hemodynamics, prognosis and guidance of therapeutic options associated with a prolonged QRS duration.     

Permanent His Bundle Pacing: The Past,Present, and Future

Long‐term right ventricular (RV) apical pacing has been associated with an increased risk of death, heart failure, and atrial fibrillation (AF). Alternative sites for RV pacing have not proven to be superior to RV apical pacing. Cardiac resynchronization therapy (CRT) using a biventricular (BiV) lead system is indicated for patients with a low left ventricular ejection fraction and QRS prolongation, but there remains about a 25–30% nonresponse rate. CRT has been less effective for nonleft bundle branch block conduction delay and with normal/low normal left ventricular function. Over the past decade, there have been more data on the feasibility and advantages of pacing at the His Bundle (HB) region. We review the anatomy and physiology of the HB, the available data on permanent HB pacing, its current and potential future applications.     

Effect of Left Ventricular Function on Long-Term Left Ventricular Pacing and Sensing Threshold

Background: The effect of left ventricular (LV) systolic function on the long-term left ventricular pacing and sensing threshold is unclear. Methods and Results: We studied the effect of LV ejection fraction (LVEF) on the LV pacing and sensing threshold in 56 patients (mean age: 70.2 ± 10.5 years) underwent permanent LV pacing using a self-retaining coronary sinus lead (Model 1055 K, St Jude Medical, USA). In 49 patients, the LV lead was implanted for conventional pacemaker indication (sick sinus syndrome = 14, heart block = 26 or slow atrial fibrillation = 9). The remaining 7 patients were implanted for congestive heart failure. The LV pacing and sensing threshold, and lead impedance were compared between patients with LVEF <40% (Group 1, n = 28) and LVEF >40% (Group 2, n = 28) during implant and at 3-month follow up. The LV pacing lead was successfully implanted in all patients without any lead dislodgement on follow-up. At implant, Group 1 patients had a significant lower R wave amplitude, but similar LV pacing threshold and lead impedance as compared to Group 2. However, at 3-month follow-up, Group 1 patients had a significantly higher LV pacing threshold compared to Group 2 patients. There were no significant differences in the sensing threshold and lead impedance between the two groups. Furthermore, there was also a significant interval increase in LV pacing threshold in Group 1 patients (0.94 ± 0.12 V) after 3 months, but not in Group 2 patients (0.16 ± 0.08 V, p < 0.01). Conclusions: The results of this study suggest that the LV systolic function has a significant impact on the long-term LV pacing threshold. The long-term left ventricular pacing threshold in patients with left ventricular systolic dysfunction increased after implant and was higher than patients with normal left ventricular systolic function.     

Acute Effects of Multisite Left Ventricular Pacing on Mechanical Dyssynchrony in Patients Receiving Cardiac Resynchronization Therapy

BackgroundA novel quadripolar left ventricular (LV) pacing lead has the ability to deliver multisite LV pacing (MSLV). We set out to characterize the safety and changes in acute mechanical dyssynchrony with MSLV in cardiac resynchronization therapy (CRT) patients.Methods and ResultsProspective multicenter study in 52 patients receiving CRT. An acute pacing protocol comprising 8 MSLV configurations covering a range of delays was compared with conventional CRT (baseline). Transthoracic tissue Doppler imaging (TDI) was used to measure the standard deviation of time to peak contraction of 12 LV segments (Ts-SD) and delayed longitudinal contraction. No ventricular arrhythmia occurred in any of the 52 patients. Complete TDI datasets were collected in 41 patients. Compared with baseline: 1) The mean Ts-SD was significantly lower for the optimal MSLV configuration (35.3 ± 36.4 vs 50.2 ± 29.1 ms; P < .001); 2) at least 1 MSLV configuration exhibited a significant dyssynchrony improvement in 63% of patients; and 3) the mean number of LV segments with delayed longitudinal contractions was significantly reduced with the optimal MSLV configuration (0.37 ± 7.99 vs 2.20 ± 0.19; P < .001).ConclusionsAcute MSLV was acutely safe, and a proportion of MSLV vectors resulted in a significant reduction in echocardiographic dyssynchrony compared with conventional CRT.     

小儿右室流出道起搏

对于一些需要安装永久起搏器的患者来讲,由于易于固定,起搏阈值低等优点,右心室起搏常将起搏电极置于心尖部,但长期随访发现,心尖部起搏可改变心室激动顺序,导致心室收缩不同步,造成二尖瓣反流、心房颤动和心功能不全。研究发现右室流出道起搏对左室功能的保护较右室心尖部起搏有利,由于右室流出道起搏靠近His束,电活动近似正常生理状态,可使左右心室电-机械活动更协调,从而抑制心室重构并保护心功能,因此,右室流出道起搏是替代右室心尖部起搏的较好选择。