急性心肌梗塞患者平板运动试验中QT离散度的变化及意义

The clinical significance of QT dispersion changes in acute myocardial infarction during treadmill testing

目的 探讨急性心肌梗塞 (AMI)患者平板运动试验 (TET)时 QT间期离散度 (QTd)的变化 ,观察其与预后的关系。 方法 3 8例 AMI 3周以上患者 ,男性 2 2例 ,女性 1 6例 ,采用 TET同步记录 1 2导联心电图 ,计算 QTd,观察运动和随访中严重室性心律失常的发生情况 ,回顾性分析其运动前后QTd的变化 ,并与冠状动脉造影 (CAG)结果加以对比。 结果 严重室性心律失常组 (A组 ) 1 5例 :TET时出现室早 >6次 /分者 2例 ,成对室早者 4例 ;其余经 1 2～ 3 2 (2 6.3± 6.1 )个月随访 ,出现频发室性早搏 5例 ,短阵室性心动过速 (室速 ) 2例 ,心室颤动 (室颤 ) 1例 ,猝死 1例。其 QTd在运动中 (98.2± 1 6.5)ms及运动后 1 h(74 .2± 2 1 .9) ms、2 h(63 .0± 2 1 .6) ms较运动前 (4 7.5± 2 0 .2 ) ms明显增加 (P<0 .0 5～0 .0 0 1 )。非严重室性心律失常组 (B组 ) 2 3例 :其 QTd在运动前、中及后 1 h、2 h[分别为 (3 8.7± 1 8.7)ms、(4 7.1± 2 6.1 ) ms、(4 4 .6± 2 3 .2 ) ms、(4 2 .9± 2 2 .9) ms]无明显变化 (P>0 .0 5)。 CAG时显示多支病变者 1 4例 ,其中 QTd>70 ms者 1 1例 ;单支病变者 8例 ,其中 QTd>70 ms者 2例 (P<0 .0 5)。 结论AMI3周以上患者运动试验后 QTd的增加影响其预后 ,如无禁忌证应做运动试验?

Objective To assess the change of QT interval dispersion(QTd)during treadmill exercise testing(TET)in patients three weeks after acute myocardial infarction(AMI) and evaluate its relation to prognosis. Methods The simultaneous standard 12 lead surface electrocardiogram tracing were recorded during TET in thirty eight patients(22 men and 16 women) with later stage AMI.Changes of QTd before and after TET were observed and analysed against whether serious ventricular tachyarrhythmia appeared in TET and follow up period 12～32(26 3±6 1)months,and also contrasted with coronary anaiography(CAG). Results Serious ventricular tachyarrhythmia appeared in fifteen patients (group A):The QTd were markedly increased during (98 2±16 5)ms and 1 hour (74 2±21 9)ms,2 hours (63 0±21 6)ms after TET respectively than that brfore TET(47 5±20 2)ms ( P <0 05～0 001).Contrarily,QTd of twenty three patients with no serious ventricular tachyarrhythmia (group B) had no change before,during and 1 hour,2 hour after TET(38 7±18 7)ms,(47 1±26 1)ms,(44 6±23 2)ms and (42 9±22 9)ms,(all P >0 05) respectively.Fourteen patients displayed multi vessel coronary lesions in CAG,and the QTd in eleven of them were greater than 70ms.Eight patients displayed singlevessel coronary lision in CAG,and QTd were greater than 70ms ( P <0 05) in two of them. Conclusion Increase of QTd during and after TET is associated with bad prognosis in part of the patients at later stage of AMI.