Shen Jiabo, Jiang Longfu, Wu Hao, Li Hengdong
Department of Cardiology, Ningbo No.2 Hospital, 41 Xibei Street , Ningbo, Zhejiang, 315010, China.
Cardiovascular Disease Clinical Medical Research Center of Ningbo, Ningbo, Zhejiang, China.
BMC Cardiovasc Disord. 2025 May 30;25(1):420. doi: 10.1186/s12872-025-04895-2.
Left bundle branch (LBB) pacing (LBBP) demonstrates clinical potential but faces challenges in confirming selective capture via dynamic electrogram (EGM) criteria.
A 69-year-old male with a complete atrioventricular block underwent LBBP implantation. Real-time EGM monitoring (high-pass/low-pass filters: 200/500 Hz) revealed an abrupt shortening of stimulus-to-V6 R-wave peak time (Sti-V6 RWPT) from 87 to 69 ms during lead deployment, indicating a transition from septal pacing to LBBP. Output reduction (1.6 V → 1.5 V/0.5 ms) eliminated myocardial excitation notches, yielding isoelectric EGMs confirming selective LBB capture. Further output reduction (1.4 V → 1.3 V/0.5 ms) prolonged Sti-V6 RWPT to 90 ms with an isoelectric interval, suggesting fascicular-level conduction delay.
This case report illustrates the electrophysiological features of a diseased conduction system via dynamic EGM analysis, despite technical limitations such as signal artifacts. While EGM morphological patterns assist in differentiating pacing modalities, further validation of these electrophysiological observations is necessary.
左束支起搏（LBBP）显示出临床潜力，但在通过动态心电图（EGM）标准确认选择性夺获方面面临挑战。
一名69岁的完全性房室传导阻滞男性接受了LBBP植入。实时EGM监测（高通/低通滤波器：200/500 Hz）显示，在导线置入过程中，刺激至V6 R波峰值时间（Sti-V6 RWPT）从87 ms突然缩短至69 ms，表明从间隔起搏转变为LBBP。输出降低（1.6 V→1.5 V/0.5 ms）消除了心肌兴奋切迹，产生等电位EGM，证实了左束支的选择性夺获。进一步降低输出（1.4 V→1.3 V/0.5 ms）使Sti-V6 RWPT延长至90 ms，并伴有等电位间期，提示束支水平传导延迟。
本病例报告通过动态EGM分析说明了病变传导系统的电生理特征，尽管存在信号伪迹等技术限制。虽然EGM形态模式有助于区分起搏方式，但这些电生理观察结果仍需进一步验证。
