Cardiac Resynchronization Therapy: A Review.

Cardiac dyssynchrony from conduction system disease may cause HF progression, particularly in patients with left ventricular (LV) systolic dysfunction.

传导系统疾病引起的心脏不同步可能导致心力衰竭进展，特别是在左心室（LV）收缩功能障碍的患者中。

observations

Electrical dyssynchrony in HF most commonly presents as left bundle-branch block and affects 20% to 30% of patients with reduced LV ejection fraction (LVEF).

心力衰竭中的电生理不同步最常见表现为左束支传导阻滞，影响20%至30%的左心室射血分数（LVEF）降低的患者。

Cardiac resynchronization therapy, which includes biventricular pacing and conduction system pacing, restores synchronous ventricular contraction and is recommended for patients with symptomatic HF despite optimal medical therapy, LVEF of 35% or less, and left bundle-branch block.

心脏再同步化治疗，包括双心室起搏和传导系统起搏，恢复了心室的同步收缩，并推荐用于尽管接受了最佳药物治疗但仍有症状的心力衰竭患者，LVEF为35%或更低，且存在左束支传导阻滞。

Delayed referral for device therapy in this population is associated with worse clinical outcomes.

在这一人群中，设备治疗的延迟转诊与更差的临床结果相关。

Resynchronization should also be considered for patients requiring chronic ventricular pacing, typically due to symptomatic bradycardia because right ventricular pacing for atrioventricular block may result in ventricular dyssynchrony and increased risk of LV systolic dysfunction.

对于需要慢性心室起搏的患者，也应考虑再同步治疗，这通常是由于症状性心动过缓，因为房室传导阻滞的右心室起搏可能会导致心室不同步和左心室收缩功能障碍风险增加。

Biventricular pacing uses 2 leads to stimulate the right ventricle and LV simultaneously; conduction system pacing uses a single lead to stimulate the His bundle or left bundle branch.

双心室起搏使用两根电极同时刺激右心室和左心室；传导系统起搏使用一根电极刺激希氏束或左束支。

An individual patient-level meta-analysisof 5 randomized clinical trials (N = 3872) reported biventricular pacing was associated with lower all-cause mortality compared with medical therapy or implantable cardioverter-defibrillator over a median follow-up of 23.7 months (13.7% vs 20.8%; hazard ratio, 0.66 [95% CI, 0.57-0.77]).

一项涉及5项随机临床试验（N=3872）的个体患者水平荟萃分析报告称，在中位随访23.7个月期间，双心室起搏与药物治疗或植入式心律转复除颤器相比，全因死亡率较低（13.7%对比20.8%；风险比为0.66 [95%置信区间，0.57-0.77]）。

A meta-analysisof 7 small randomized clinical trials, including 408 patients with HF and LVEF of 40% or less, reported that compared with biventricular pacing, conduction system pacing was associated with improvement in LVEF (mean difference, 2.06%; P = .03).

一项包含7项小型随机临床试验的荟萃分析，共纳入408名心力衰竭（HF）患者，左心室射血分数（LVEF）为40%或以下，报告称与双心室起搏相比，传导系统起搏与LVEF的改善相关（平均差异，2.06%；P = .03）。

An observational study of 1778 patients with LVEF of 35% or less undergoing cardiac resynchronization therapy reported conduction system pacing was associated with lower rates of HF hospitalization (12% vs 19%; hazard ratio, 0.67 [95% CI, 0.52-0.86]).

一项观察性研究涉及1778名接受心脏再同步化治疗（cardiac resynchronization therapy，CRT）且LVEF为35%或以下的患者，报告称传导系统起搏与心力衰竭住院率降低相关（12%对比19%；风险比，0.67 [95% 置信区间，0.52-0.86]）。

A trial of 249 patients without HF undergoing permanent pacing for atrioventricular block-related bradycardia reported lower rates of pacing-induced cardiomyopathy, defined as a decrease in LVEF of at least 10% to less than 50% after conduction system pacing vs right ventricular pacing (6% vs 15%; P = .01).

一项涉及249名未患心力衰竭患者因房室传导阻滞相关心动过缓而接受永久性起搏治疗的试验报告称，与右心室起搏相比，传导系统起搏后发生起搏诱发性心肌病的比率较低，定义为起搏后左心室射血分数(LVEF)至少下降10%至低于50% (6% 对比 15%; P = .01)。

conclusions_and_relevance

Cardiac dyssynchrony due to conduction system disease occurs in 20% to 30% of patients with HF and systolic dysfunction.

在20%至30%的心力衰竭和收缩功能障碍患者中，由于传导系统疾病导致的心脏不同步发生。

Cardiac resynchronization therapy restores synchronous ventricular activation in patients with HF, reduced LVEF, and left bundle-branch block, or in those requiring chronic ventricular pacing, and may improve LV function, decrease HF hospitalizations, and reduce mortality.

心脏再同步化治疗能够恢复心力衰竭、左心室射血分数降低和左束支传导阻滞患者的心室同步激活，或者对于需要长期心室起搏的患者，可能改善左心室功能，减少心力衰竭住院次数，并降低死亡率。