Department of Cardiology, First Affiliated Hospital, Nanjing Medical University, Nanjing, China.
College of Computing, Michigan Technological University, Houghton, Michigan, USA.
Pacing Clin Electrophysiol. 2021 Mar;44(3):472-480. doi: 10.1111/pace.14147. Epub 2021 Jan 31.
Chronic right ventricular (RV) pacing is associated with an increased incidence of heart failure and mortality. Left bundle branch (LBB) pacing could produce near-physiological electrical activation and mechanical synchrony. We aimed to report the effects of upgrading to LBB pacing in heart failure patients after chronic RV pacing.
The indications included pacing-induced cardiomyopathy (PICM) in Group 1 and heart failure after RV pacing with left ventricular ejection fraction (LVEF) ≥ 50% in Group 2. LBB pacing was achieved by penetrating the pacing lead to the subendocardium of left-sided interventricular septum through the venous access. Left ventricular activation time (LVAT) was measured from the pacing stimulus to the ascending peak of lead V5 or V6. All patients underwent clinical and echocardiographic evaluations before and after upgrading.
Totally 27 patients (13 in Group 1 and 14 in Group 2) were consecutively enrolled. The mean follow-up time after upgrade was 10.4 ± 6.1 months. Paced QRS duration was significantly shortened from 174.1 ± 15.8 milliseconds to 116.6 ± 11.7 milliseconds (p < .0001). The mean LVAT was 83.2 ± 11.7 milliseconds. LVEF increased from 40.3 ± 5.2% before upgrading to 48.1 ± 9.5% at follow-up in patients with PICM. Serum N-terminal probrain natriuretic peptide levels decreased and New York Heart Association classification improved in both groups. No upgrade-related complications were observed.
Upgrading to LBB pacing was feasible and effective with improved cardiac function in heart failure patients with both reduced and preserved LVEF after RV pacing.
慢性右心室（RV）起搏与心力衰竭和死亡率的发生率增加有关。左束支（LBB）起搏可以产生接近生理的电激活和机械同步性。我们旨在报告在慢性 RV 起搏后心力衰竭患者中升级为 LBB 起搏的效果。
适应证包括 1 组中的起搏诱导性心肌病（PICM）和 2 组中的 RV 起搏后心力衰竭伴左心室射血分数（LVEF）≥50%。通过经静脉通路将起搏导线穿透到左室间隔的心内膜下，实现 LBB 起搏。从起搏刺激到导联 V5 或 V6 的上升峰测量左心室激活时间（LVAT）。所有患者在升级前后均进行临床和超声心动图评估。
共有 27 例患者（1 组 13 例，2 组 14 例）连续入选。升级后平均随访时间为 10.4±6.1 个月。起搏 QRS 时限明显缩短，从 174.1±15.8 毫秒缩短至 116.6±11.7 毫秒（p<0.0001）。平均 LVAT 为 83.2±11.7 毫秒。PICM 患者的 LVEF 从升级前的 40.3±5.2%增加到随访时的 48.1±9.5%。两组血清 N 末端脑利钠肽前体水平降低，纽约心脏协会分级改善。未观察到与升级相关的并发症。
在慢性 RV 起搏后 LVEF 降低和保留的心力衰竭患者中，升级为 LBB 起搏是可行且有效的，可以改善心功能。
