Liu Wen, Fulati Zibire, Tian Fangyan, Xu Nuo, Cheng Yufei, Zhao Yingjie, Chen Haiyan, Shu Xianhong
Department of Echocardiography, Zhongshan Hospital, Fudan University, Shanghai, China; Department of Cardiology, Shanghai Institute of Cardiovascular Disease, Zhongshan Hospital, Fudan University, Shanghai, China; Shanghai Institute of Medical Imaging, Fudan University, Shanghai, China.
Department of Echocardiography, Zhongshan Hospital, Fudan University, Shanghai, China; Department of Cardiology, Shanghai Institute of Cardiovascular Disease, Zhongshan Hospital, Fudan University, Shanghai, China; Shanghai Institute of Medical Imaging, Fudan University, Shanghai, China.
Heart Rhythm. 2025 May;22(5):1298-1306. doi: 10.1016/j.hrthm.2024.08.059. Epub 2024 Sep 2.
Left bundle branch pacing (LBBP) is a novel physiological pacing modality. However, whether it delivers comparable efficacy with different capture sites in patients with heart failure remains unclear.
This study aimed to assess the association between different pacing sites and the response of LBBP.
Forty-three consecutive patients with heart failure, referred for successful LBBP implantation, were prospectively recruited in this study. Patients were assigned to 3 subgroups according to the paced QRS complex morphology (left bundle branch trunk pacing [LBTP], left posterior fascicular pacing, or left anterior fascicular pacing groups). Echocardiograms and electrocardiograms were recorded and analyzed at baseline and 6-month follow-up.
The response rate was 95.0%, 88.2%, and 83.3% in LBTP, left posterior fascicular pacing, and left anterior fascicular pacing groups, respectively. All subgroups were efficient in narrowing the QRS complex (QRS complex narrowing: 38.1 ± 10.8 ms, 36.4 ± 12.6 ms, and 40.8 ± 10.8 ms) and improving cardiac function (LVEF improvement： 25.7% ± 8.1%, 15.3% ± 8.1%, and 18.8% ± 4.4%). Compared with left fascicular pacing, LBTP resulted in longer peak left ventricular activation time (76.5 ± 10.2 ms vs 82.3 ± 6.5 ms; P = .037) and shorter duration from intrinsicoid deflection in V1 or V2 to QRS end (128.0 ± 6.0 ms vs 113.3 ± 5.2 ms; P＜.0001), along with better improvement in septal systolic longitudinal strain (P = .007) and lateral-septal myocardial loading inhomogeneity (P = .036). Linear regression analysis further revealed that left bundle branch capture sites were strongly associated with the improvement in peak strain dispersion (model R = 0.586; P = .042) and LVEF (model R = 0.425; P < .0001).
Different left bundle branch capture sites led to a subtle difference in mechanical synchrony, which may, in turn, affect LVEF improvement in patients with heart failure.
左束支起搏（LBBP）是一种新型的生理性起搏方式。然而，在心力衰竭患者中，不同夺获部位的左束支起搏疗效是否相当仍不清楚。
本研究旨在评估不同起搏部位与左束支起搏反应之间的关联。
本研究前瞻性纳入了43例因成功植入左束支起搏器而转诊的心力衰竭患者。根据起搏QRS波形态，将患者分为3个亚组（左束支主干起搏[LBTP]组、左后分支起搏组或左前分支起搏组）。在基线和随访6个月时记录并分析超声心动图和心电图。
LBTP组、左后分支起搏组和左前分支起搏组的反应率分别为95.0%、88.2%和83.3%。所有亚组均能有效缩窄QRS波（QRS波缩窄：38.1±10.8 ms、36.4±12.6 ms和40.8±10.8 ms）并改善心功能（左心室射血分数[LVEF]改善：25.7%±8.1%、15.3%±8.1%和18.8%±4.4%）。与左分支起搏相比，LBTP导致左心室激活峰值时间更长（76.5±10.2 ms对82.3±6.5 ms；P = 0.037），从V1或V2导联的类本位曲折到QRS波终点的时间更短（128.0±6.0 ms对113.3±5.2 ms；P＜0.0001），同时，室间隔收缩期纵向应变改善更好（P = 0.007），侧壁-室间隔心肌负荷不均一性改善更好（P = 0.036）。线性回归分析进一步显示，左束支夺获部位与峰值应变离散度改善（模型R = 0.586；P = 0.042）和LVEF改善（模型R = 0.425；P < 0.0001）密切相关。
不同的左束支夺获部位导致机械同步性存在细微差异，进而可能影响心力衰竭患者的LVEF改善。
