Natale A, Sra J, Axtell K, Maglio C, Dhala A, Blanck Z, Deshpande S, Jazayeri M, Akhtar M
Electrophysiology Laboratory, Milwaukee Heart Institute of Sinai Samaritan Medical Center, Wisconsin.
J Cardiovasc Electrophysiol. 1994 Dec;5(12):988-94. doi: 10.1111/j.1540-8167.1994.tb01140.x.
Previous studies have suggested that coronary artery bypass surgery is sufficient to prevent recurrence of sudden death in patients with critical coronary artery stenosis presenting with ventricular fibrillation or polymorphic ventricular tachycardia. We present our experience in patients with one or more episodes of sudden death associated with documented ventricular fibrillation or polymorphic ventricular tachycardia and severe operable coronary artery disease who underwent defibrillator implant at the time of bypass surgery.
Fifty-eight consecutive patients (age 63 +/- 8 years) were included in this study. Eighteen of the 58 patients had no evidence of previous myocardial infarction. The mean ejection fraction was 37 +/- 13%. All patients underwent electrophysiologic study before and after revascularization. At the time of first defibrillator discharge, each patient was reevaluated to exclude the presence of ischemia. The benefits of defibrillator implant were estimated comparing the projected survival based upon defibrillator discharge preceded by syncope or presyncope with survival curves generated including total death and sudden plus cardiac death. After a mean follow-up of 4.6 +/- 2 years, 22 patients received appropriate shocks preceded by syncope or presyncope, and an additional 19 patients received asymptomatic shocks. At 4 years, survival free of total death was 71.2%, and the projected survival was 58.8% (P < 0.05). Multivariate analysis showed that ejection fraction lower than 30% and induction of arrhythmia with one or two extrastimuli (S2, S3) were independent predictors for defibrillator discharge. None of the remaining variables including age, gender, number of bypasses, history of myocardial infarction, and type of arrhythmias induced were predictive for death and occurrence of shocks.
In patients with ventricular fibrillation and polymorphic ventricular tachycardia, bypass surgery does not protect from recurrence of life-threatening arrhythmias, and, as in our population, defibrillator implant may have significant impact on survival.
先前的研究表明，冠状动脉搭桥手术足以预防因严重冠状动脉狭窄伴心室颤动或多形性室性心动过速而出现的心脏性猝死复发。我们报告了在接受搭桥手术时植入除颤器的患者的经验，这些患者有一次或多次与记录在案的心室颤动或多形性室性心动过速相关的心脏性猝死发作，且患有严重的可手术治疗的冠状动脉疾病。
本研究纳入了58例连续患者（年龄63±8岁）。58例患者中有18例无既往心肌梗死证据。平均射血分数为37±13%。所有患者在血运重建前后均接受了电生理检查。在首次除颤器放电时，对每位患者进行重新评估以排除缺血的存在。通过比较基于晕厥或先兆晕厥前除颤器放电的预计生存率与包括全因死亡及心脏性猝死加心脏死亡的生存曲线，评估植入除颤器的益处。平均随访4.6±2年后，22例患者在晕厥或先兆晕厥前接受了适当的电击，另有19例患者接受了无症状电击。4年时，无全因死亡的生存率为71.2%，预计生存率为58.8%（P<0.05）。多变量分析显示，射血分数低于30%以及用一个或两个期外刺激（S2、S3）诱发心律失常是除颤器放电的独立预测因素。其余变量，包括年龄、性别、搭桥数量、心肌梗死病史及诱发的心律失常类型，均不能预测死亡和电击的发生。
对于心室颤动和多形性室性心动过速患者，搭桥手术不能预防危及生命的心律失常复发，而且，如我们的研究人群所示，植入除颤器可能对生存率有显著影响。
