冠心病患者平板运动试验中QT离散度变化的临床意义

The Significance of QT Dispersion During Exercise Treadmill Test in Patients With Coronary Heart Disease

目的 :探讨平板运动试验中冠心病患者与冠状动脉正常者QT离散度 (QTd)变化的意义。方法 :分组经冠状动脉造影术证实的 14例冠心病者与 16例冠脉造影正常者平板运动试验前、中、后体表心电图QTd变化。结果 :运动前、中、后冠心病组QTd分别为 4 3 15± 16 2 1ms、6 9 82± 18 36ms及 4 8 2 3±11 2 8ms ,而冠状动脉正常组分别为 2 9 2 2± 4 2 1ms、2 8 6 2± 6 33ms及 2 7 2 6± 7 6 4ms。两组P相比均 <0 0 1;冠脉组QTd运动中与运动前后相比P均 <0 0 1,而冠脉正常者差异并无显著性 ;以运动中QTd≥6 0ms判为异常 ,诊断冠心病的敏感性为 85 7% ,特异性为 92 3%。结论 :冠心病患者平板运动试验中QTd显著增加 ,可作为判定平板运动试验的心电学指标之一 。

Objective:To investigate the clinical significance of QT dispersion during exercise treadmill test in patients with and without coronary artery disease.Method:QT dispersion of 12-lead surface ECG was measured when ST segments depression was more than 1 mm or typical angina occurred or submaximal heart rate was achieved,and after exercise treadmill test,14 patients with coronary artery disease and 16 patients with normal coronary arteries was identified by coronary angiography.Result:The QT dispersions were significantly increased in patients with coronary artery disease before,during and after exercise(43.15±16.21ms,69.82±18.36ms,48.23±11.28ms respectively),compared with those in patients with normal coronary arteries(29.22±4.21ms,28.62±6.33ms,27.26±7.64ms respectively),all P<0.01,in patients with coronary artery disease,QT dispersions were significantly increased during exercise compared with those before and after exercise(P<0.005).There were no significant changes in QT dispersion in patients with normal coronary arteries before,during and after exercise.Stress QT dispersion of ≥60ms,the sensitivity is 85.7% and specificity is 92.3% for the diagnosis of coronary artery disease.Conclusion:QT dispersssion is significantly increased in patients with coronary artery disease during exercise test QT dispersion during exercise treadmill test could be used as a sensitive and specific index for the diagnosis of coronary heart disease.