Minneapolis Heart Institute East, Allina Health, St. Paul, Minnesota.
Minneapolis Heart Institute East, Allina Health, St. Paul, Minnesota; Cardiology Division, Department of Medicine, University of Minnesota, Minneapolis, Minnesota; Heart Rhythm Science Center, Minneapolis Heart Institute Foundation, Minneapolis, Minnesota.
Heart Rhythm. 2022 Dec;19(12):1965-1973. doi: 10.1016/j.hrthm.2022.07.016. Epub 2022 Aug 5.
Nonresponse to cardiac resynchronization therapy (CRT) occurs in ∼30%-50% of patients. There are no well-accepted clinical approaches for optimizing CRT in nonresponders.
The purpose of this study was to demonstrate the effect of CRT optimization using electrical dyssynchrony mapping on left ventricular (LV) function, size, and dyssynchrony in selected patients with nonresponse/incomplete response to CRT.
We studied 39 patients with underlying left bundle branch block or interventricular conduction delay who had an LV ejection fraction of ≤40% after receiving CRT and had significant electrical dyssynchrony. Electrical dyssynchrony was measured at multiple atrioventricular delays and interventricular delays. The QRS area between combinations of 9 anterior and 9 posterior electrograms (QRS area under the curve) was calculated, and cardiac resynchronization index (CRI) was defined as the percent change in QRS area under the curve compared to native conduction. Electrical dyssynchrony maps depicted CRI over the wide range of settings tested. Patients were programmed to an optimal device setting, and echocardiograms were recorded 5.9 ± 3.7 months postoptimization.
CRI increased from 49.4% ± 24.0% to 90.8% ± 10.5%. CRT optimization significantly improved LV ejection fraction from 31.8% ± 4.7% to 36.3% ± 5.9% (P < .001) and LV end-systolic volume from 108.5 ± 37.6 to 98.0 ± 37.5 mL (P = .009). Speckle-tracking measures of LV strain significantly improved by 2.4% ± 4.5% (transverse; P = .002) and 1.0% ± 2.6% (longitudinal; P = .017). Aortic to pulmonic valve opening time, a measure of interventricular dyssynchrony, significantly (P = .040) decreased by 14.9 ± 39.4 ms.
CRT optimization of electrical dyssynchrony using a novel electrical dyssynchrony mapping technology significantly improves LV systolic function, LV end-systolic volume, and mechanical dyssynchrony. This methodology offers a noninvasive, practical clinical approach to treating nonresponders and incomplete responders to CRT.
约 30%-50%的心脏再同步治疗（CRT）患者无应答。目前尚无公认的临床方法可用于优化无应答者的 CRT。
本研究旨在证明使用电不同步映射技术优化 CRT 对 CRT 无应答/部分应答患者的左心室（LV）功能、大小和不同步的影响。
我们研究了 39 名患有左束支传导阻滞或室间传导延迟的患者，这些患者在接受 CRT 后 LV 射血分数≤40%，且存在明显的电不同步。在多个房室延迟和室间延迟下测量电不同步。计算 9 个前向和 9 个后向心电图之间的 QRS 区域（QRS 曲线下面积），并定义心脏再同步指数（CRI）为与固有传导相比 QRS 曲线下面积的百分比变化。电不同步图描绘了在广泛的测试设置下的 CRI。将患者程控至最佳设备设置，并在优化后 5.9±3.7 个月记录超声心动图。
CRI 从 49.4%±24.0%增加到 90.8%±10.5%。CRT 优化使 LV 射血分数从 31.8%±4.7%显著提高至 36.3%±5.9%（P<0.001），LV 收缩末期容积从 108.5±37.6 降至 98.0±37.5 mL（P=0.009）。LV 应变的斑点追踪测量值分别显著提高了 2.4%±4.5%（横向；P=0.002）和 1.0%±2.6%（纵向；P=0.017）。衡量室间不同步的主动脉瓣到肺动脉瓣开放时间显著缩短了 14.9±39.4 ms（P=0.040）。
使用新型电不同步映射技术优化电不同步的 CRT 可显著改善 LV 收缩功能、LV 收缩末期容积和机械不同步。这种方法为治疗 CRT 无应答和部分应答患者提供了一种非侵入性、实用的临床方法。
