Bonomini María P, Ortega Daniel F, Logarzo Emilio, Mangani Nicolás, Paolucci Analía
Instituto Argentino de Matemática, 'Alberto P. Calderón' CONICET, Buenos Aires, Argentina.
Clínica San Camilo, Buenos Aires, Argentina.
J Electrocardiol. 2022 Mar-Apr;71:47-52. doi: 10.1016/j.jelectrocard.2022.01.004. Epub 2022 Jan 31.
High percentages of pacing were associated to maximal symptomatic and mortality benefit from cardiac resynchronization therapy (CRT). Loss of CRT pacing is linked to intrinsic ventricular activation preceding biventricular pacing (BiV), as it occurs in patients with atrial fibrillation (AF). Last generation CRT devices incorporate the ventricular sense response (VSR) mechanism to maintain biventricular pacing in patients with atrial arrhythmias. This work aimed to characterize electrical dyssynchrony differences among baseline, BiV and VSR pacing, and determine whether the VSR mode is as beneficial as the BiV mode in terms of electrical dyssynchrony.
Thirty-two patients implanted with CRT devices were retrospectively studied. All patients presented non-ischemic dilated myocardiopathy and complete left bundle branch block (LBBB). Every patient went through baseline, BiV and VSR pacing while recording the 12‑lead ECG. Electrical dyssynchrony was assessed by a dyssynchrony index (DIn) obtained from correlation analysis on the 12‑lead ECG.
When comparing with baseline, VSR pacing improved QRS duration (178 ± 22 ms vs 158 ± 43 ms, baseline vs VSR, p < 0.05) and so did BiV pacing (178 ± 22 ms vs 142 ± 20 ms, baseline vs BiV, p < 0.05). However, electrical dyssynchrony only improved at BiV pacing (2.86±0.6 vs 0.54±0.8, baseline vs BiV, p < 0.05) while VSR showed average DIn values similar to those at baseline.
VSR pacing did not improve the electrical synchrony while did shorten QRS duration in this sample population. Therefore, VSR paced beats would fall in the category of inefficient BiV and may not be the preferred alternative in patients with CRT and AF.
高比例的起搏与心脏再同步治疗（CRT）带来的最大症状改善及死亡率获益相关。CRT起搏的丧失与双心室起搏（BiV）之前的心室固有激活有关，心房颤动（AF）患者中就会出现这种情况。最新一代的CRT设备采用了心室感知反应（VSR）机制，以维持房性心律失常患者的双心室起搏。本研究旨在描述基线、BiV和VSR起搏之间的电不同步差异，并确定就电不同步而言，VSR模式是否与BiV模式一样有益。
对32例植入CRT设备的患者进行回顾性研究。所有患者均患有非缺血性扩张型心肌病和完全性左束支传导阻滞（LBBB）。每位患者在记录12导联心电图时均经历了基线、BiV和VSR起搏。通过对12导联心电图进行相关性分析获得的不同步指数（DIn）评估电不同步情况。
与基线相比，VSR起搏改善了QRS波时限（基线时为178±22毫秒，VSR时为158±43毫秒，p<0.05），BiV起搏也有同样效果（基线时为178±22毫秒，BiV时为142±20毫秒，p<0.05）。然而，仅BiV起搏时电不同步得到改善（基线时为2.86±0.6，BiV时为0.54±0.8，p<0.05），而VSR的平均DIn值与基线时相似。
在本样本人群中，VSR起搏虽缩短了QRS波时限，但未改善电同步性。因此，VSR起搏的搏动属于无效BiV类别，可能不是CRT和AF患者的首选替代方案。
