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。     

右室流出道间隔部应用螺旋电极固定起搏对心功能的影响分析

目的比较右室流出道(RVOT)间隔部起搏和右室心尖部起搏(RVA)对心功能的影响,评估螺旋电极进行右室流出道间隔部起搏技术的可行性与安全性。方法选择有永久起搏器植入适应证的患者21例,分为右室流出道间隔部起搏组(试验组),右心室心尖部起搏组(对照组),以超声心动图(UCG)和心电图评价两组术前、术后血流动力学和QRS波宽度差异。结果术后平均随访6个月,结果显示RVOT起搏血流动力学优于RVA起搏(P<0.05),RVOT起搏QRS波宽度较RVA组缩短,有统计学意义(P<0.01)。结论利用螺旋电极进行右室流出道间隔部起搏基本可行且较为安全,右室流出道间隔部起搏的血流动力学参数优于右室心尖部。     

右室双部位起搏电生理学和血液动力学效应

1　右室流出道起搏的血液动力学效应右室双部位起搏位点为右室流出道或间隔部及右室心尖。其实,右室流出道起搏在国内已有开展[10],只是右室流出道作为心尖部起搏失败而选择的后备电极放置部位,但其应用亦显示右室流出道起搏有良好的电(心电呈ＲＳ型)及临床效果。吴印生等[11]对右室流出道起搏的患者应用ＳＷＡＮＧＡＮＺ漂浮导管进行了血流动力学研究,并与心尖部起搏对比,结果表明右室流出道起搏的每搏心输出量(ＳＶ)、每搏心输出指数(ＳＶＩ)、心输出量(ＣＯ)及心输出指数(ＣＩ)均较右室心尖部起搏明显增高,详见附表。与国外报道相似[12]…     

右心室流出道间隔部起搏对左室功能的影响

目的比较右心室流出道间隔部（RVOT）起搏与右心室心尖部（RVA）起搏的血流动力学差异，评估右室流出道间隔部起搏技术的可行性与安全性。方法选择有永久起搏器植入适应证的患者36例，分为右心室流出道间隔部起搏组（试验组），右心室心尖部起搏组（对照组），以超声心动图（UCG）评价右室流出道间隔部与右室心尖部起搏的中远期血流动力学差异。结果术后平均随访10个月，结果显示RVOT起搏血流动力学优于RVA起搏，差异有统计学意义（P〈0．05）。结论初步研究结果提示：利用螺旋电极进行右室流出道间隔部起搏基本可行且较为安全，右室流出道间隔部起搏的血流动力学参数优于右室心尖部。     

主动固定螺旋电极在右室流出道间隔部起搏中的应用体会

目的探索采用主动固定螺旋电极行右室间隔部起搏的临床可行性。方法随机选择54例需要安装双腔起搏器的患者行右室流出道间隔部起搏,将心室起搏螺旋电极先后定位于右室心尖部及右室流出道间隔部并测试起搏参数。结果右室流出道间隔部电极定位成功率为98.15%,该部位起搏参数满足起搏要求,同时起搏的QRS波时限较心尖部变窄(130.45±18.24msvs153.11±20.10ms,P<0.001)。结论采用主动固定螺旋电极行右室流出道间隔部起搏安全性高、可行性好。     

右室起搏部位的研究进展

右室不同部位起搏具有不同的心电生理学和血流动力学效应,右室流入道间隔部起搏能保持相对正常的心室激动顺序,流出道起搏能获得较好的血流动力学效应,His束及His束旁是理想的心室生理性起搏,但操作较复杂。间隔上部及双部位起搏是否能改善血流动力学尚有待进一步研究。     

不同起搏部位对心脏病患者近期血流动力学及心脏结构的影响

心室电激动顺序和心室收缩同步性均是影响心功能的重要因素,在起搏方式一定时,起搏部位通过对心室激动顺序的不同对心功能有不同的影响。本文通过对右室心尖部（RVA）起搏和右室流出道（RVOT）起搏患者的血流动力学及心脏结构改变的比较,以探讨其对患者近期血流动力学和心脏结构的影响。     

右室流出道间隔部起搏的研究进展

长期以来右室心尖部( RVA)一直作为右心室起搏电极常规植入部位.研究表明RVA并不是理想的起搏部位.为此,人们试图寻找更理想的心室起搏部位.由于RVOT间隔部靠近His束,更接近正常传导系统.RVOT间隔部起搏理论上能产生更好的血流动力学效应.但是,以往RVOT间隔部起搏研究结果并不一致.本文就右室流出道间隔部起搏的研究进展进行综述.     

右心室不同部位起搏对血流动力学的影响

多年来,人们一直怀疑长期右室心尖部起搏改变了心室激动及收缩顺序,导致心室收缩不同步,最终将诱发心力衰竭。为了减轻这种不良后果,有学者提出了更生理的起搏部位如右室中位间隔和高位间隔起搏替代右室心尖部起搏。为此,我们采用超声心动图和心电图技术评估了右室不同部位起搏对血流动力学的影响,现报告如下。     

右心室流出道起搏

近来有越来越多的证据表明传统的右室心尖部起搏对心脏有着不利的影响,用其他部位来替代心尖起搏已经成为研究的热点,其中研究最多的是右室流出道起搏。现综述右室流出道起搏的优点和右室流出道的解剖结构及具体起搏部位,电极的定位方法等,以期为今后的临床工作提供一点帮助,     

右室心尖部起搏与右室流出道起搏对Ⅲ度房室传导阻滞患者疗效的对比研究

目的:比较右室心尖部起搏与右室流出道起搏对Ⅲ度房室传导阻滞患者心室间运动同步性及左室内运动同步性,以及对患者心功能的影响。方法:选取因Ⅲ度及高度房室传导阻滞患者置入双腔起搏器患者共38例。其中心室电极置入右室流出道者20例(RVOT组),置入右室心尖部18例(RVA组),超声心动图术前测量左室舒张末内径(LVEDD),左室收缩末内径(LVESD)、左室射血分数(LVEF)、E/A值、心室间激动延迟时间(IVMD)、室间隔与左心室后壁间收缩延迟时间(SPWMD)。术后1个月、12个月随访。结果:术后1个月,与RVOT组比较,RVA组IVMD、SPWMD明显延长[IVMD(39.83±6.01)∶(31.95±7.86)ms,P=0.02],[SP-WMD(97.83±20.81)∶(84.6±10.89)ms,P=0.023]。术后12个月,与ROVT组比较,RVA组LVEDD明显增大[(49.11±2.39)∶(47.4±1.96)mm,P=0.02],LVESD明显增大[(34.28±3.41)∶(32.5±1.5)mm,P=0.04];LVEF明显降低[(59.56±3.38)∶(62.8±2.14)%,...     

Comparison of the Acute Hemodynamic Effect of Right Ventricular Apex,Outflow Tract,and Dual‐Site Right Ventricular Pacing

Background: We studied the acute effect of pacing at the right ventricular outflow tract (RVOT), right ventricular apex (RVA) and simultaneous RVA and RVOT—dual‐site right ventricular pacing (DuRV) in random order on systolic function using impedance cardiography. Methods: Seventy‐three patients (46 males), aged 52–89 years (mean 71.4 years) subjected to routine dual chamber pacemaker implantation with symptomatic chronic II or atrioventricular block, were included to the study. Results: DuRV pacing resulted in significantly higher cardiac index (CI) in comparison to RVOT and RVA and CI at RVOT was higher than at RVA pacing (2.46 vs 2.35 vs 2.28; P < 0.001). In patients with ejection fraction >50% significantly higher CI was observed during DuRV pacing when compared to RVOT and RVA pacing and there was no difference of CI between RVOT and RVA pacing (2.53 vs 2.41 vs 2.37; P < 0.001). In patients with ejection fraction <50%, DuRV and RVOT pacing resulted in significantly higher CI in comparison to RVA pacing while no difference in CI was observed between RVOT and DuRV pacing (2.28 vs 2.21 vs 2.09; P < 0.001). Conclusion: Dual‐site right ventricular pacing in comparison to RVA pacing improved cardiac systolic function. RVOT appeared to be more advantageous than RVA pacing in patients with impaired, but not in those with preserved left ventricular function. No clear hemodynamic benefit of DuRV in comparison to RVOT pacing in patients with impaired systolic function was observed. Ann Noninvasive Electrocardiol 2010;15(4):353‐359     

Hemodynamic improvement by right ventricular septal pacing in elderly patients with chronic atrial fibrillation and slow ventricular response

Background and objectives Right ventricular apical (RVA) pacing has been reported impairing left ventricular (LV) performance. Alternative pacing sites in right ventricle (RV) has been explored to obtain better cardiac function. Our study was designed to compare the hemodynamic effects of right ventricular septal (RVS) pacing with RVA pacing. Methods Ten elderly patients with chronic atrial fibrillation (AF) and long RR interval or slow ventricular response (VR) received VVI pacing. The hemodynamic difference between RVS and RVA pacing were examined by transthoracic echocardiography (TTE). Results Pacing leads were implanted successfully at the RVA and then RVS in all patients without complication. The left ventricular (LV) parameters, measured during RVA pacing including left ventricular ejection fraction (LVEF), FS, stroke volume (SV) and peak E wave velocity (EV) were decreased significantly compared to baseline data, while during RVS pacing, they were significantly better than those during RVA pacing. However, after 3-6 weeks there was no statistical significant difference between pre- and post- RVS pacing. Conclusions The LV hemodynamic parameters during RVA pacing were significantly worse than baseline data. The short term LV hemodynamic parameters of RVS pacing were significantly better than those of RVA pacing; RVS pacing could improve the hemodynamic effect through maintaining normal ventricular activation sequence and biventricular contraction synchrony in patients with chronic AF and slow ventricular response.(J Geriatr Cardiol 2005,2(2): 103-106).     

右心室不同部位起搏对心脏收缩同步性及心功能的影响

目的比较右心室流出道（right ventricular outflow tract,RVOT）起搏与右心窀心尖部（riht ventficular apex,RVA）起搏对心脏收缩同步性指标及收缩功能的影响。方法2004年1月至2005年1月在我院植入VVL／VVIR,DDD／DDDR起搏器的患者,随机接受RVA起搏和RVOT起搏。植入前检查12导联体表心电罔及超声心动图,记录QRS时限、左心室舒张末内径（LVEDD）、左心房内径（LAD）、左心事射血分数（LVEF）。植入后记录心室起搏状态下的QRS时限。随访时间为2年,随访内容包括LVEDD、LAD、LVEF,同时应用脉冲组织多普勒技术测定心室问激动延迟（IVMD）以及左心室内收缩同步性指标（Ts-SD）。结果共随访30例患者,其中RVA起搏17例,RVOT起搏13例,两组患者间年龄、性别及心血管疾病等基本情况筹异无统计学意义。植入前两组患者问QRS时限、LVEDD、LAD及LVEF差异无统计学意义,植入后RVOT起搏状态下QRS时限较RVA起搏明显缩短[（140．15±11．36）ms对（160．76±23．68）ms,P=0．033],植入后两组间IVMD[（25．7±9．1）mS对（36．7±10．0）ms,P=0．076]比较差异无统计学意义,两组问Ts—SD（13．34ms对42．96ms,P=0．001）比较差异有统计学意义;植入后随访两年,两组患者间LAD差异无统计学意义[（43±6）ms对（42±9）ms,P=0．759],同RVA组相比,RVOT组LVEDD缩小[（5．10±0．76）mm对（5．28±0．40）mm,P=0．048],LVEF明显增加（0．56±0．04对0．52±0．02,P=0．001）。结论同右心窄流出道起搏相比,右心室心尖部起搏对患者心功能呈负性影响,且加重左心室内不同步收缩。     

Right ventricular outflow versus apical pacing in pacemaker patients with congestive heart failure and atrial fibrillation

INTRODUCTION: Prior studies suggest that right ventricular apical (RVA) pacing has deleterious effects. Whether the right ventricular outflow tract (RVOT) is a more optimal site for permanent pacing in patients with congestive heart failure (CHF) has not been established. METHODS AND RESULTS: We conducted a randomized, cross-over trial to determine whether quality of life (QOL) is better after 3 months of RVOT than RVA pacing in 103 pacemaker recipients with CHF, left ventricular (LV) systolic dysfunction (LV ejection fraction < or = 40%), and chronic atrial fibrillation (AF). An additional aim was to compare dual-site (RVOT + RVA, 31-ms delay) with single-site RVA and RVOT pacing. QRS duration was shorter during RVOT (167 +/- 45 ms) and dual-site (149 +/- 19 ms) than RVA pacing (180 +/- 58 ms, P < 0.0001). At 6 months, the RVOT group had higher (P = 0.01) role-emotional QOL subscale scores than the RVA group. At 9 months, there were no significant differences in QOL scores between RVOT and RVA groups. Comparing RVOT to RVA pacing within the same patient, mental health subscale scores were better (P = 0.03) during RVOT pacing. After 9 months of follow-up, LVEF was higher (P = 0.04) in those assigned to RVA rather than RVOT pacing between months 6 and 9. After 3 months of dual-site RV pacing, physical functioning was worse (P = 0.04) than during RVA pacing, mental health was worse (P = 0.02) than during RVOT pacing, and New York Heart Association (NYHA) functional class was slightly better (P = 0.03) than during RVOT pacing. There were no other significant differences between RVA, RVOT and dual-site RV pacing in QOL scores, NYHA class, distance walked in 6 minutes, LV ejection fraction, or mitral regurgitation. CONCLUSION: In patients with CHF, LV dysfunction, and chronic AF, RVOT and dual-site RV pacing shorten QRS duration but after 3 months do not consistently improve QOL or other clinical outcomes compared with RVA pacing.     

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)     

Optimal right ventricular pacing site in chronically implanted patients: A prospective randomized crossover comparison of apical and outflow tract pacing

ObjectivesTo evaluate the long-term functional and hemodynamic effects of right ventricular outflow tract (RVOT) pacing by comparison with right ventricular apical (RVA) pacing.BackgroundAcute studies have suggested that RVOT pacing could significantly improve cardiac performance in comparison with RVA pacing but no data are available in chronically implanted patients.MethodsSixteen patients with chronic atrial tachyarrhythmia and complete AV block were included. Left ventricular ejection fraction (LVEF) was ≥40% in ten and <40% in six. Patients were implanted with a standard DDDR pacemaker connected to two ventricular leads. A screw-in lead was placed at the RVOT and connected to the atrial port. A second lead was positioned at the RVA and connected to the ventricular port. Right ventricular outflow tract and RVA pacing was achieved by programming either the AAIR or the VVIR mode respectively. Four months later patients were randomized so as to undergo either RVOT or RVA pacing for three months according to a blind crossover protocol. Apart from the pacing mode, programming remained unchanged throughout the study. At the end of each period, NYHA class, LVEF, exercise time and maximal oxygen uptake were assessed.ResultsNo significant difference was observed between the two modes for all the parameters analyzed. These identical results were observed in all patients globally, in patients with LVEF ≥40% as in those with LVEF <40%.ConclusionsWithin the limits of this study, no symptomatic improvement or hemodynamic benefit was noted after three months of RVOT pacing, by comparison with RVA pacing.     

右心室流出道间隔部起搏对左心室功能的影响

目的比较右心室流出道间隔部(RVOT)起搏与右心室心尖部(RVA)起搏的血流动力学差异;评估RVOT起搏技术的可行性与安全性。方法选择有永久起搏器置入适应证的患者75例。根据术者建议和患者意愿分为RVOT组(40例)和RVA组(35例)。所有房室传导阻滞及病窦综合征合并一度房室传导阻滞患者采用双腔起搏双腔感知触发抑制型起搏模式,心房颤动伴长间歇患者采用抑制型心室按需起搏模式。比较2组的血流动力学差异。结果 RVOT组的QRS波宽度较RVA组缩窄(23.2±28.7)ms,差异有统计学意义(P<0.01)。与RVA组比较,RVOT组LVEF、左心室短轴缩短率明显升高,左心室舒张末容积明显下降(P<0.05,P<0.01)。与术前比较,RVA组LVEF、左心室短轴缩短率明显下降,左心室舒张末容积明显升高,差异有统计学意义(P<0.01)。结论利用螺旋电极进行RVOT起搏可行且较为安全。RVOT起搏的血流动力学参数优于RVA。     

右心腔不同部位起搏的慢性血流动力学对比研究

比较右心耳 (RAA)、右室流出道 (RVOT)与右室心尖部 (RVA)起搏的慢性血流动力学效果 ,评价RVOT起搏的可行性。2 9例患者 ,9例RAA起搏、8例RVOT起搏、12例RVA起搏 ,分别在术前及术后 6 .11± 4 .0 1、5 .38± 2 .92、5 .5 0± 2 .88个月 ,用多普勒超声心动图观察右心腔不同部位起搏的慢性血流动力学参数 ,包括左室射血分数(LVEF)、左室内径缩短分数 (SF)、肺动脉瓣口峰值血流速度 (PV)、二尖瓣口E峰血流速度 (E)、A峰血流速度 (A)及比值 (E/A)。结果 :RAA起搏时 ,LVEF、SF分别下降为 4 .5 6 %± 3.71% ,3.33%± 2 .83% ,P <0 .0 5。RVOT起搏时 ,LVEF、SF、E/A分别下降为 6 .38%± 4 .6 9% ,4 .13%± 2 .75 % ,1.2 9± 0 .5 1,P <0 .0 1。RVA起搏时 ,LVEF、SF、PV、E、E/A分别下降为 1.4 2 %± 5 .32 % ,7.92 %± 3.96 % ,8.5 8± 11.33cm/s,8.17± 9.6 3cm/s,0 .2 7± 0 .2 9,P <0 .0 1或0 .0 5。A则上升为 7.91± 11.2 6cm/s(P <0 .0 5 )。RVOT起搏与RVA起搏相比LVEF、SF明显改善 (P均 <0 .0 5 ) ,且临床症状明显减轻 ;与右房起搏相比 ,E/A下降 (P <0 .0 5 ) ,其他指标在随访期内未显示出统计学意义上的差别。结论 :对于心功能较好的患者 ,右心腔不同部位起搏对慢性血流动力学均有一定程度的负面影响 ;R