Jiang Zhixin, Wu Tian, Wu Yixian, Chen Zenghong, Yang Wen, Chen Chongchong, Zhou Xiujuan, Shan Qijun
Department of Cardiology, Jiangsu Province Hospital, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China.
Front Cardiovasc Med. 2022 Mar 17;9:838708. doi: 10.3389/fcvm.2022.838708. eCollection 2022.
The present study aimed to compare the effects of left bundle branch area pacing (LBBAP) on cardiac function and clinical outcomes in patients with left bundle branch block (LBBB) and left ventricular ejection fraction (LVEF) >35 vs. ≤35%.
Thirty-six consecutive patients with LBBB and LVEF <50% were enrolled. All patients were followed up for a mean of 6 months. The successful LBBAP was defined as a paced QRS complex presented as right bundle branch block (RBBB) morphology and QRSd < 130 ms. Echocardiography parameters, pacing parameters and clinical outcomes were collected. The successful LBBAP was achieved in 77.8% of all cases (28/36). In LVEF > 35% group (70 ± 8 years, 9 male), the success rate was 81.0% (17/21). QRSd significantly decreased from 174 ± 23 ms to 108 ± 13 ms ( < 0.001). The pacing threshold and R-wave amplitude were 0.6 ± 0.2 V @ 0.5 ms and 12 ± 7 mV, respectively. In LVEF ≤ 35% group (69 ± 5 years, 9 male), the success rate was 73.3% (11/15) with QRSd decreasing from 188 ± 25 ms to 107 ± 11 ms ( < 0.001). The hyperresponders to LBBAP (functional recovery and LVEF ≥ 50%) in LVEF > 35% group was 52.9%, which were almost twice of that in LVEF ≤ 35% group (33.3%). Whether patients had LBBAP or left ventricular septal pacing (LVSP), patients in the LVEF > 35% group showed significantly lower incidence of heart failure hospitalizations or death from any cause (hazard ratio in LVEF > 35% group, 0.22; 95%CI, 0.06 to 0.75, = 0.011).
LBBAP can significantly shorten the QRSd and improve cardiac function in LBBB patients with either LVEF > 35 or ≤ 35%. LBBAP should be considered as an effective therapy for preventing the deterioration of cardiac function in early-stage heart failure patients with LBBB and LVEF > 35%.
本研究旨在比较左束支区域起搏（LBBAP）对左束支传导阻滞（LBBB）且左心室射血分数（LVEF）>35%与≤35%患者的心功能及临床结局的影响。
连续纳入36例LBBB且LVEF<50%的患者。所有患者平均随访6个月。成功的LBBAP定义为起搏QRS波群呈右束支传导阻滞（RBBB）形态且QRS时限（QRSd）<130 ms。收集超声心动图参数、起搏参数及临床结局。所有病例中77.8%（28/36）成功完成LBBAP。在LVEF>35%组（70±8岁，9例男性），成功率为81.0%（17/21）。QRSd从174±23 ms显著降至108±13 ms（<0.001）。起搏阈值和R波振幅分别为0.6±0.2 V @ 0.5 ms和12±7 mV。在LVEF≤35%组（69±5岁，9例男性），成功率为73.3%（11/15），QRSd从188±25 ms降至107±11 ms（<0.001）。LVEF>35%组中对LBBAP超反应者（功能恢复且LVEF≥50%）为52.9%，几乎是LVEF≤35%组（33.3%）的两倍。无论患者接受LBBAP还是左心室间隔起搏（LVSP），LVEF>35%组患者因任何原因导致的心力衰竭住院或死亡发生率均显著较低（LVEF>35%组的风险比为0.22；95%置信区间，从0.06至0.75，P=0.011）。
LBBAP可显著缩短LBBB患者（无论LVEF>35%还是≤35%）的QRSd并改善心功能。LBBAP应被视为预防LBBB且LVEF>35%的早期心力衰竭患者心功能恶化的有效治疗方法。
