Tereshchenko Larisa G, Henrikson Charles A, Stempniewicz Peter, Han Lichy, Berger Ronald D
Division of Cardiology, Department of Medicine, Johns Hopkins Hospital, Baltimore, Maryland 21287, USA.
Pacing Clin Electrophysiol. 2011 Mar;34(3):357-64. doi: 10.1111/j.1540-8159.2010.02974.x. Epub 2010 Nov 22.
Antiarrhythmic and proarrhythmic effects of cardiac resynchronization therapy (CRT) remain controversial. We hypothesized that reverse electrical remodeling (RER) with CRT is associated with reduced frequency of ventricular tachyarrhythmias (VTs).
The width of native and paced QRS was measured in lead II electrocardiogram before and 13 ± 7 months after implantation of a CRT defibrillator device in 69 patients (mean age 66.3 ± 13.9; 39 males [83%]) with bundle branch block (BBB) (41 patients with left BBB and three patients with bifascicular block) or nonspecific intraventricular conduction delay (25 patients, 36%), and New York Heart Association class III-IV heart failure. Biventricular pacing was inhibited for 10 seconds to record native QRS. RER was defined as a decrease in the native QRS duration ≥10 ms compared to preimplant. Patients were followed prospectively 24 ± 13 months after assessment for electrical remodeling.
RER was observed in 22 patients (32%), among whom QRS duration decreased by 30.9 ± 14.1 ms (P < 0.00001) with similar heart rate and QRS morphology. Native QRS duration increased by 10.3 ± 16.6 ms in the other 47 patients (68%) (P = 0.0001). Baseline mean ejection fraction did not differ between patients with and those without RER (24.9 ± 10.0 vs 24.2 ± 8.6%, NS). During 2 ± 1 years of further follow-up, 19 patients had VTs and 12 patients died. RER was associated with a fourfold decrease in the risk of death or sustained VTs requiring appropriate implantable cardioverter-defibrillator therapies, whichever came first (hazard ratio 0.25; 95% confidence interval 0.08-0.85; P = 0.026).
RER of the native conduction with CRT is associated with decreased mortality and antiarrhythmic effect of CRT.
心脏再同步治疗（CRT）的抗心律失常及促心律失常作用仍存在争议。我们推测CRT所致的逆向电重构（RER）与室性快速心律失常（VT）频率降低有关。
在69例（平均年龄66.3±13.9岁；39例男性[83%]）有束支传导阻滞（BBB）（41例左束支传导阻滞和3例双分支传导阻滞）或非特异性室内传导延迟（25例，36%）且纽约心脏协会心功能分级为III-IV级心力衰竭的患者中，于植入CRT除颤器装置前及植入后13±7个月，在II导联心电图上测量自身及起搏QRS波宽度。双心室起搏被抑制10秒以记录自身QRS波。RER定义为自身QRS波时限较植入前降低≥10毫秒。在评估电重构后对患者进行前瞻性随访24±13个月。
22例患者（32%）观察到RER，其中QRS波时限在心率及QRS波形态相似的情况下降低了30.9±14.1毫秒（P<0.00001）。其他47例患者（68%）自身QRS波时限增加了10.3±16.6毫秒（P=0.0001）。有RER与无RER的患者基线平均射血分数无差异（24.9±10.0%对24.2±8.6%，无显著性差异）。在2±1年的进一步随访期间，19例患者发生VT，12例患者死亡。RER与死亡或需要适当植入式心律转复除颤器治疗的持续性VT风险降低四倍相关（风险比0.25；95%置信区间0.08-0.85；P=0.026）。
CRT引起的自身传导RER与死亡率降低及CRT的抗心律失常作用相关。
