QT离散度在冠心病患者运动试验时的意义

The significance of QT dispersion during exercise treadmill test in patients with coronary heart disease

目的 探讨活动平板试验前后冠心病患者与冠状动脉正常者的QT离散度 (QTr)变化的意义。方法 分析经冠状动脉造影证实 34例冠心病患者与 32例冠状动脉造影正常者活动平板试验前后体表 12导联心电图QTr变化。结果 运动前、后冠心病组QTr分别为 (5 3 88± 14 6 8)ms与 (6 6 0 3± 11 4 0 )ms (P <0 0 0 1) ,而冠状动脉造影正常者分别为 (35 4 7± 9 95 )ms与 (36 75± 7 2 2 )ms (P >0 0 5 ) ,运动前、后两组相比P均 <0 0 0 1;冠心病组QTr运动后与运动前相比P <0 0 0 1,而冠脉正常组差异无显著性意义 ,以运动后QTr≥ 5 0ms判为异常 ,诊断冠心病的敏感性为 94 1% ,特异性为 90 6 % ,预测准确性为 92 4 %。结论 冠心病组活动平板试验后QTr进一步显著增加 ,提示运动后的QTr有助于反映冠状动脉病变及心肌缺血程度 。

Objective To investigate the clinical significance of QT dispersion during exercise treadmill test in patient with and without coronary heart disease(CHD).Methods The changes of QTr of 12 lead surface ECG measured before and after exercise treadmill test (ETT) were analyzed in 34 patients with CHD and 32 patients with normal coronary arteries identified by coronary angiography.Results The QTr were significantly increased in patient with CHD before and after exercise (53 88±14 68)ms,[(66 03±11 40)ms respectively]compared with those in patient with normal coronary arteries [(35 47±9 95)ms, (36 75±7 22)ms, respectively]all P<0 001. In patients with CHD, QTr were significantly increased after exercise compared with those before exercise (P<0 001=.There were no significant changes in QTr in patient with normal coronary arteries before and after exercise. Stress QTr≥50ms had a sensitivity of 94 1%,specificity of 90 6%,accuracy of 92.4% for the diagnosis of CHD.Conclusion QTr is significantly increased in patents with CHD after exercise test. A larger QTr after exercise may reflect the extent of myocardial ischemia. QTr during exercise treadmill test cold be used as a sensitive and specific index for the diagnosis of coronary heart disease.