微伏级T波电交替在急性心肌梗死不同再灌注时间中的临床意义

Clinical significance of microvolt T-wave alternans during different reperfusion periods in acute myocardial infarction

目的探讨时域法微伏级T波电交替(microvolt T-wave electrical alternation,MTWA)在急性心肌梗死(acute myocardial infarction,AMI)不同再灌注时间的动态变化规律,以及与再灌注后室性心律失常发生的相关性。方法102例AMI患者行经皮冠状动脉介入(percutaneous coronary intervention,PCI)术后分为室性心动过速(室速)组和非室速组,对比分析两组临床资料及心电学各项参数。结果102例患者中47例出现室速,55例无室速;室速组平均心室率、超敏肌钙蛋白浓度、MTWA、震荡初始明显高于非室速组,而震荡斜率、射血分数明显小于非室速组(P均<0.05);两组SDNN无统计学差异;MTWA预测室性心动过速的灵敏度、特异度、阳性预测值、阴性预测值均比其他4个指标高;最长一串室速出现前15 min MTWA值为(82.9±10.2)μV,明显高于30、60 min时的MTWA值(P<0.05);室速出现的时间节点多数集中在血流再通后1~3 h。结论MTWA可预测AMI患者PCI术后再灌注恶性室性心律失常的发生,血流再通后1~3 h室速发生的概率最大,对于MTWA阳性者此时间段及PCI术前应用胺碘酮等抗心律失常药物预防恶性室性心律失常发生,可增加患者术后存活率,预防猝死发生。

Objective To investigate the dynamic change of microvolt T-wave electrical alternation(MTWA)in acute myocardial infarction(AMI)during different reperfusion periods and its correlation with ventricular arrhythmia after reperfusion.MethodsOne hundred and two AMI patients were divided into ventricular tachycardia(VT)group and nonVT group after percutaneous coronary intervention(PCI),and the clinical data and ECG parameters of the two groups were compared and analyzed.ResultsFortyseven among the 102 patients had VT and 55 had no VT.The average ventricular rate,hypersensitive troponin,MTWA and turbulence onset(TO)in VT group were significantly higher than those in the non-VT group,while turbulence slope(TS)and EF were significantly lower than those in the nonVT group(P<0.05).The results showed that there is no significant difference in SDNN between the two groups.MTWA had the highest sensitivity,specificity,positive predictive value and negative predictive value in predicting VT.The MTWA value of(82.9±10.2)μV appeared at 15 minutes before the appearing of the longest string of VT,which was significantly higher than that of 30 minutes and 60 minutes(P<0.05).Most of the time nodes of VT occurred in 1-3 hours after the blood flow recanalization.ConclusionsMTWA can predict the occurrence of reperfusion malignant VT in AMI patients after PCI,and the incidence of VT is the highest in 1-3 hours after blood flow recanalization.For MTWA positive patients during this period and before PCI,antiarrhythmic drugs such as amiodarone should be applied to prevent the occurrence of malignant VT,increase the postoperative survival rate of patients,and prevent sudden death.