Division of Arrhythmia and Electrophysiology, Shizuoka Saiseikai General Hospital, Shizuoka, Japan.
Circ J. 2012;76(12):2799-806. doi: 10.1253/circj.cj-12-0811. Epub 2012 Sep 4.
Right atrial (RA) appendage (RAA) pacing is reported to impair hemodynamic benefits of cardiac resynchronization therapy (CRT) through a considerable delay of left atrial (LA) contraction, which compromises appropriate balance of atrioventricular (AV) and left ventricular (LV) synchrony. Potential usefulness of Bachmann's bundle (BB) pacing to solve the problem remains to be confirmed.
Atrial synchrony and LV performance was investigated by echocardiography in 25 patients undergoing pacemaker implantation with preserved AV conduction and LV function (Group I), and 15 patients receiving CRT (Group II). In Group I, RAA pacing (AAI mode, n=10) increased P-wave duration (PWD) and RA-to-LA contraction delay (IAMD) compared with sinus rhythm (132±14 and 35±12 ms vs. 108±16 and 13±13 ms, P<0.001). The delayed LA contraction was associated with early interruption of LV filling, leading to an impairment of LV performance (Tei index: 0.43±0.12 vs. 0.34±0.09, P<0.01). BB pacing (AAI, n=15) did not cause such undesirable effects. In Group II, RA (BB)-paced biventricular pacing (DDD) reduced PWD and IAMD compared with RA-sensed biventricular pacing (VDD) (102±14 and -3±13 ms vs. 117±10 and 21±18 ms, P<0.001). This restoration of atrial synchrony was associated with significant improvement of LV performance (Tei index: 0.56±0.18 vs. 0.62±0.16, P<0.05).
BB pacing preserves atrial synchrony, and might be more favorable than RAA pacing for maximizing hemodynamic efficacy of CRT.
右心房（RA）心耳部（RAA）起搏通过相当大的左心房（LA）收缩延迟报告为损害心脏再同步治疗（CRT）的血液动力学益处，这损害了房室（AV）和左心室（LV）同步的适当平衡。Bachmann 束（BB）起搏解决这个问题的潜在有用性仍有待证实。
通过超声心动图研究了 25 例保留 AV 传导和 LV 功能的起搏器植入患者（I 组）和 15 例接受 CRT 的患者（II 组）的心房同步和 LV 性能。在 I 组中，与窦性心律相比，RAA 起搏（AAI 模式，n=10）增加了 P 波持续时间（PWD）和 RA 至 LA 收缩延迟（IAMD）（132±14 和 35±12 ms 与 108±16 和 13±13 ms，P<0.001）。延迟的 LA 收缩与 LV 充盈早期中断有关，导致 LV 性能受损（Tei 指数：0.43±0.12 与 0.34±0.09，P<0.01）。BB 起搏（AAI，n=15）没有引起这种不良影响。在 II 组中，与 RA 感知的双心室起搏（VDD）相比，RA（BB）起搏的双心室起搏（DDD）降低了 PWD 和 IAMD（102±14 和 -3±13 ms 与 117±10 和 21±18 ms，P<0.001）。这种心房同步的恢复与 LV 性能的显著改善相关（Tei 指数：0.56±0.18 与 0.62±0.16，P<0.05）。
BB 起搏保持了心房同步性，并且可能比 RAA 起搏更有利于最大化 CRT 的血液动力学效果。
