Background

Novel metrics of electrical dyssynchrony based on multi-electrode mapping and ECG-based markers of fusion are better predictors of cardiac resynchronization therapy (CRT) response than QRS duration.

Objective

To describe a new methodology for measuring electrical synchrony based on wavefront fusion and electrocardiographic cancellation in patients with CRT and its potential for CRT optimization.

Methods

Patients with left bundle branch block (LBBB) type conduction and CRT (n = 84) were studied at multiple device settings using an ECG belt (53 anterior and posterior electrodes). The area between combinations of anterior and posterior curves (AUC) was calculated and cardiac resynchronization index (CRI) defined as percent change in AUC compared to LBBB.

Results

In 14 patients with complete heart block or atrial fibrillation, CRI at optimal ventriculo-ventricular delay (VVD) (40 ± 19 ms) was significantly higher than with simultaneous biventricular pacing (BiVp) (90 ± 8.6% vs. 54.2 ± 24.2%, p < 0.001). In all 70 patients paced LV-only, LV-paced wavefront was ahead of native wavefront at short atrio-ventricular delay (AVD) and CRI increased with increase in AVD, peaked, and then decreased. Optimal CRI during LV-only pacing was significantly better than optimal CRI with simultaneous BiVp (89.6 ± 8% vs. 64.4 ± 22%, p < 0.001), and occurred at AVD 68 ± 22 ms less than the atrial-RV sensed interval. With sequential BiVp, best CRI was 83.9 ± 13% (with LV preactivation of 40 ± 20 ms). Best CRI at any setting was markedly better than CRI at standard setting (91.6 ± 7.7% vs. 52.7 ± 23.3, p < 0.001).

Conclusion

We describe a novel non-invasive investigational tool that quantifies wavefront fusion and electrical dyssynchrony, and may allow for individualized CRT optimization.

中文翻译：

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心力衰竭患者左束支传导阻滞和心脏再同步治疗的电波前融合：对优化的意义。

背景

与QRS持续时间相比，基于多电极映射和基于ECG的融合标志物的新的电不同步指标是心脏再同步治疗（CRT）反应的更好预测指标。

目的

描述一种基于波前融合和心电图抵消的CRT患者电同步测量新方法及其对CRT优化的潜力。

方法

左束支传导阻滞（LBBB）型传导和CRT（n  = 84）的患者使用ECG传送带（53个前后电极）在多种设备设置下进行了研究。计算前后曲线（AUC）组合之间的面积，并将心脏再同步指数（CRI）定义为与LBBB相比AUC的变化百分比。

结果

在14例完全性心脏传导阻滞或心房颤动的患者中，最佳心室-心室延迟（VVD）（40±19 ms）时的CRI显着高于同期双心室起搏（BiVp）（90±8.6％对54.2±24.2％，p  <0.001）。在所有仅使用左心室起搏的70例患者中，短暂的房室延迟（AVD）时，左心室起搏的波前领先于自然波前，并且CRI随AVD的增加而增加，达到峰值，然后下降。纯LV起搏期间的最佳CRI明显优于同时BiVp的最佳CRI（89.6±8％vs. 64.4±22％，p <0.001），并且发生在比房室RV感测间隔短的AVD 68±22 ms处。采用顺序BiVp时，最佳CRI为83.9±13％（LV预激活为40±20 ms）。任何设置下的最佳CRI均明显优于标准设置下的CRI（91.6±7.7％与52.7±23.3，p  <0.001）。

结论

我们描述了一种新颖的非侵入性研究工具，可以量化波前融合和电不同步，并可能允许个性化的CRT优化。