First Department of Cardiology, Interventional Electrocardiology and Hypertension, Jagiellonian University, Medical College, Kraków, Poland.
First Department of Cardiology, Interventional Electrocardiology and Hypertension, Jagiellonian University, Medical College, Kraków, Poland.
Heart Rhythm. 2021 Jun;18(6):935-943. doi: 10.1016/j.hrthm.2021.02.021. Epub 2021 Mar 4.
During left bundle branch (LBB) area pacing, it is important to confirm that capture of the LBB, and not just capture of only adjacent left ventricular (LV) myocardium, has been achieved.
The purpose of this study was to establish electrocardiographic (ECG) criteria for LBB capture. We hypothesized that because LBB pacing results in physiological depolarization of the LV, then the native QRS can serve as a reference for diagnosis of LBB capture in the same patient.
Only patients with evidence of LBB capture (QRS morphology transition) were included. Several QRS characteristics were compared between the native rhythm and different types of LBB area capture.
A total of 357 ECGs (124 patients) were analyzed: 118 with native rhythm, 124 with nonselective LBB capture, 69 with selective LBB capture, and 46 with LV septal capture. Our hypotheses that during LBB capture the paced V6 R-wave peak time (RWPT; measured from QRS onset) equals the native V6 RWPT and that the paced V6 RWPT (measured from the stimulus) equals the LBB potential to V6 R-wave peak interval were positively validated. Criteria based on these rules had sensitivity and specificity of 88.2%-98.0% and 85.7%-95.4%, respectively. Moreover, 100% specific V6 RWPT cutoff for LBB capture diagnosis in patients with narrow QRS/right bundle branch block was determined to be 74 ms.
We showed equivalency of LV activation times on ECG during native and paced LBB conduction. Therefore, if V6 RWPT is longer during pacing, this finding is indicative of lack of LBB capture.
在左束支（LBB）区域起搏时，重要的是要确认已实现 LBB 的捕获，而不仅仅是仅捕获相邻的左心室（LV）心肌。
本研究旨在建立 LBB 捕获的心电图（ECG）标准。我们假设，由于 LBB 起搏导致 LV 的生理性去极化，因此可以将固有 QRS 用作同一患者中 LBB 捕获诊断的参考。
仅包括具有 LBB 捕获（QRS 形态过渡）证据的患者。比较了固有节律与不同类型的 LBB 区域捕获之间的几种 QRS 特征。
共分析了 357 份心电图（124 例患者）：118 份固有节律，124 份非选择性 LBB 捕获，69 份选择性 LBB 捕获和 46 份 LV 间隔捕获。我们的假设是，在 LBB 捕获期间，起搏的 V6 R 波峰时间（RWPT；从 QRS 起始测量）等于固有 V6 RWPT，并且起搏的 V6 RWPT（从刺激测量）等于 LBB 电位至 V6 R 波峰间隔，得到了积极验证。基于这些规则的标准的敏感性和特异性分别为 88.2％-98.0％和 85.7％-95.4％。此外，在 QRS/右束支阻滞较窄的患者中，用于 LBB 捕获诊断的 100％特异性 V6 RWPT 截止值确定为 74 ms。
我们证明了在固有和起搏的 LBB 传导过程中，LV 激活时间在心电图上具有等效性。因此，如果起搏时 V6 RWPT 较长，则表示缺乏 LBB 捕获。
