Sze Edward, Daubert James P
Electrophysiology Section, Division of Cardiology, Department of Medicine, Duke University, Durham, NC, USA.
Duke Clinical Research Institute, Duke University, Durham, NC, USA.
J Interv Card Electrophysiol. 2018 Aug;52(3):343-352. doi: 10.1007/s10840-018-0407-2. Epub 2018 Jul 17.
With the emergence of cardiac resynchronization therapy (CRT) as a powerful tool to reverse left ventricular dysfunction in patients with left bundle branch block (LBBB), there is increasing awareness that LBBB-induced dyssynchrony may be a primary cause of heart failure with reduced ejection fraction (HFrEF). Current guidelines for implanting CRT require at least 3 months of guideline-directed medical therapy (GDMT) before device implantation in the hopes that medications will reverse cardiomyopathy and obviate the need for device therapy. However, no randomized controlled trial demonstrating efficacy of medications ever stratified outcomes by patients with conduction abnormalities. Consequently, CRT, not GDMT, may be a more effective first-line therapy for patients with LBBB and HFrEF. This review evaluates the evidence for LBBB-induced cardiomyopathy, examines the rationale for GDMT in this population, and presents the evidence for direct implantation of CRT. It is likely that many patients would benefit from earlier intervention with CRT, though about 25% of patients with LBBB and HFrEF may respond to GDMT.
随着心脏再同步治疗（CRT）作为逆转左束支传导阻滞（LBBB）患者左心室功能障碍的有力工具的出现，人们越来越意识到LBBB引起的不同步可能是射血分数降低的心力衰竭（HFrEF）的主要原因。目前植入CRT的指南要求在植入设备前至少进行3个月的指南指导药物治疗（GDMT），希望药物能逆转心肌病并避免设备治疗的需要。然而，没有一项随机对照试验证明药物疗效曾按传导异常患者分层结果。因此，对于LBBB和HFrEF患者，CRT而非GDMT可能是更有效的一线治疗方法。本综述评估了LBBB引起的心肌病的证据，研究了该人群中GDMT的基本原理，并展示了直接植入CRT的证据。尽管约25%的LBBB和HFrEF患者可能对GDMT有反应，但许多患者可能会从CRT的早期干预中受益。
