微伏级T波电交替与室性心动过速的临床研究

目的室性心动过速（室速）是器质性心脏病猝死的主要机制.微伏级T波电交替（microvolt T wave alternans,MTWA）是近年来无创评价和预测室速/心室颤动（室颤）及心脏性猝死的新方法.本研究的目的是探讨MTWA与室速的关系及其临床意义.方法用system剑桥心脏诊断系统（Cambridge Heart.Heartwave^TM）,以频谱法检测45例健康志愿者及82例可疑室性心律失常者（其中有资料记载的室速48例）的MTWA.结果MTWA阳性主要见于陈旧性心肌梗死、冠心病、心肌病等,它与室速有一定的相关性（r=0.37,P＜0.01）.器质性心脏病室速组MTWA阳性率高于非器质性心脏病室速组（P＜0.01）,非器质性心脏病室速组MTWA阳性率与健康人组差异无统计学意义（P＞0.05）.MTWA诊断器质性心脏病室速的敏感性75.00%,特异性92.10%,诊断符合率87.03%.结论MTWA与器质性心脏病室速相关,可用于室速患者的危险分层.

A clinical study of microvolt T wave alternans and ventricular tachycardia

Objective Ventricular tachycardia(VT)was the most common mechanism responsible for sudden cardiac death in patients with organic heart disease. Microvolt T wave alternans(MTWA)is a new noninvasive technique for identifying patients at increased risk of cardiac arrest from ventricular tachy arrhythmias. The aim of this study was to investigate clinical significant relationship between MTWA and VT. Methods MTWA was assessed in 45 healthy volunteers and 82 patients with suspected ventricular arrhythmias(48 with documented ventricular tachycardia)with spectral domain using Cambridge Heart Heartwave TM system. Results Positive MTWA was observed in patients with old myocardial infarction, coronary artery disease and cardiomyopathy. There was a significant correlation between MTWA and VT(r=0.37, P<0.01). Positive MTWA was more in patients with VT associated with organic heart disease compared to those without organic heart disease(P<0.01). Whereas there was no difference between VT patients without organic heart disease and normal individuals(P>0.05). The senstivity, specificity and predictive accuracy of MTWA for organic VT were 75.00%,92.10% and 87.03%, respectively. Conclusion MTWA is related to VT in patients with organic heart disease, it can be used to identify high risk patients for VT.