右心室室性心动过速患者时域法微伏级T波电交替特征及其临床意义

目的探讨右心室室性心动过速患者时域法微伏级T波电交替（MTWA）特征及其临床意义。方法采用活动平板时域法分别对35例致心律失常性右心室心肌病（ARVC）患者其中男性28例，平均年龄（38．6±11，0）岁]、10例特发性右心室室性心动过速（IRVT）患者其中男性7例，平均年龄（41．9±15．4）岁]和60例健康对照者男性42例，平均年龄（41．0±14．9）岁]进行MTWA检测，记录胸前V1～V6导联的MTWA值，确定胸前各导联的最大值，以Max Valt表示。分析比较不同组别各导联MTWA值及Max Valt值的差异。结果ARVC组各导联MTWA值和Max Valt值均明显高于对照组（P〈0．01）；IRVT组各导联的MTWA值和Max Valt值比对照组升高，但差异无统计学意义（P〉0．05）；ARVC组和IRVT组比较，V4导联MTWA值及MaxVah值明显较高（P〈0．05）；接受者操作特性（receiver operating characteristic，ROC）曲线分析表明，以Max Valt〉11．5μV鉴别诊断ARVC的敏感性为74．3％，特异性为80．0％；ARVC组中，近一年内有持续性室速发生的患者较无室速发作患者V2～V6导联的MTWA值以及Max Valt值的差异有统计学意义。结论渐量修正平均时域法检测显示，ARVC患者MTWA值和Max Valt值均明显升高．MTWA佰可以反映ARVC患者近期室性心动过速的发作。

The features and clinical significance of microvolt T-wave alternans in patients with right ventricular tachycardia

Objective To explore the features and clinical significance of microvoh T-wave alternans (MTWA) using modified moving average analyses in patients with right ventricular tachycardia. Methods MTWA voltages were detected using modified moving average analyses with exercise in 35 patients with arrhyth-mogenic right ventricular cardiomyopathy(ARVC)tachycardia, in 10 patients with idiopathic right ventricular tachycardia(IRVT),and in 60 healthy persons as control. MTWA voltages in precordial lead V1～V6 were re-corded. The maximal MTWA voltages were expressed as MaxValt. The MTWA voltages were compared among ARVC group,the IRVTgroup,and control group. Results The voltages of MTWA in all precordial leads were higher in ARVC group than those in control group (P<0.01). There was no significant difference between IRVT and control group(P>0.05). The voltages of MTWA in lead V4 and the MaxVah were higher in ARVC group than those in IRVT group (P<0.05). The receiver-operating characteristics (ROC) curves for MTWA showed that the sensitivity and specificity for predicting ARVC was 74.3% and 80.0% ,respectively,when the 11.5 μV was chosen as cutpaint value of MaxValt. In ARVC group,the voltages of MTWA in lead V2、V3、V4、V6 and MaxValt were greater in those with occurrence of sustained ventricular tachycardia in previous one year than in those without ventricular tachycardia occurrence (P<0.05). Conclusions The voltages of MTWA de-tected with modified moving average method are significantly higher in ARVC patients. MTWA might be related to the late occurrence of ventricular tachycardia in ARVC patients.