Clinica San Camilo, Buenos Aires, Av Angel Gallardo 899, C1405DJI, CABA, Argentina.
Hospital Universitario Austral, Buenos Aires, Av. JD Peron 1500, Pilar, Pcia. Bs As, Argentina.
Europace. 2018 May 1;20(5):816-822. doi: 10.1093/europace/eux098.
His bundle pacing has shown to prevent detrimental effects from right ventricular apical pacing (RVA) and proved to resynchronize many conduction disturbances cases. However, the extent of His bundle pacing resynchronization is limited. An optimized stimulation waveform could expand this limit when implemented in His bundle pacing sets. In this work, we temporarily implemented RVA and Non-selective His bundle pacing with a biphasic anodal-first waveform (AF-nHB) and compared their effects against sinus rhythm (SR).
Fifteen patients referred for electrophysiologic study with conduction disturbances, cardiomyopathy and ejection fraction below 35% were enrolled for the study. The following acute parameters were measured: QRS duration, left ventricular activation (RLVT), time of isovolumic contraction (IVCT), ejection fraction (EF), and dP/dtmax. QRS duration and RLVT decreased markedly under AF-nHB (SR: 169 ± 34 ms vs. nHB: 116 ± 31 ms, P < 0.0005) while RVA significantly increased QRS duration (SR: 169 ms vs. RVA: 198 ms, P < 0.05) and did not change RLVT (P = NS). Consistently, IVCT moderately decreased under AF-nHB (SR: 238 ms vs. RVA: 184 ms, P < 0.05 vs. SR) and dP/dtmax showed a 93.35 [mmHg] average increase under AF-nHB against SR. Also, T-wave inversions were observed during AF-nHB immediately after SR and RVA pacing suggesting the occurrence of cardiac memory.
AF-nHB corrected bundle branch blocks in patients with severe conduction disturbances, even in those with dilated cardiomiopathy, outstanding from RVA. Also, the occurrence of cardiac memory during AF-nHB turned up as an observational finding of this study.
希氏束起搏已被证明可防止右心室心尖部起搏（RVA）的有害影响，并已证明可使许多传导障碍病例得到再同步化。然而，希氏束起搏的再同步化程度是有限的。当在希氏束起搏设备中实施时，优化的刺激波形可以扩大这个限制。在这项工作中，我们暂时实施了 RVA 和非选择性希氏束起搏，使用双相阳极优先波形（AF-nHB），并将其与窦性节律（SR）进行了比较。
我们招募了 15 名因传导障碍、心肌病和射血分数低于 35%而接受电生理研究的患者进行这项研究。测量了以下急性参数：QRS 持续时间、左心室激活（RLVT）、等容收缩时间（IVCT）、射血分数（EF）和 dP/dtmax。在 AF-nHB 下，QRS 持续时间和 RLVT 明显缩短（SR：169 ± 34 ms 比 nHB：116 ± 31 ms，P < 0.0005），而 RVA 显著增加 QRS 持续时间（SR：169 ms 比 RVA：198 ms，P < 0.05），但不改变 RLVT（P = NS）。同样，IVCT 在 AF-nHB 下适度降低（SR：238 ms 比 RVA：184 ms，P < 0.05 比 SR），dP/dtmax 显示出 93.35 [mmHg] 的平均增加，与 SR 相比。此外，在 SR 和 RVA 起搏后立即出现 AF-nHB 时观察到 T 波反转，提示存在心脏记忆。
AF-nHB 纠正了严重传导障碍患者的束支传导阻滞，即使是在扩张型心肌病患者中，也优于 RVA。此外，在 AF-nHB 期间发生的心脏记忆是本研究的一个观察结果。
