运动试验阴性的男性患者QT离散度的变化对冠心病的诊断价值

Value of QT dispersion in the interpretation of treadmill exercise electrocardiograms of patients without exercise-induced ST-segment depression

目的 观测运动试验中QT离散度的改变是否能够增加运动试验对冠心病的检出率。方法分析60例因有明显的临床指征而行冠状动脉造影的男性患者,术前患者运动试验均未诱发ST段压低。其中34例为两年期间连续冠状动脉造影结果未见显著狭窄者(对照组),26例为两年期间连续冠状动脉狭窄者(实验组)。两组分别测量运动试验前及运动试验后1、3、5分钟12导心电图最长和最短的QT间期的差值,即QT离散度(QTd)。结果 运动停止即刻实验组QTd明显较对照组大。以运动停止即刻QTd大于60ms为指标诊断冠心病的敏感性为84.6％,特异性为76.5％,符合率为87.7％。结论 对运动试验未能诱发出ST段压低的人群。以运动停止即刻QTd大于60ms作为诊断冠心病的指标,可以提高诊断的准确性。

Objective To determine weather the QT dispersion (QTd) may improve the accuracy of exercise testing in patients with coronary artery disease (CAD), who do not show a ST-segment depression. Methods Exercise ECGs were analyzed in 60 male patients who had undergone coronary angiography. None of them showed a ST-segment depression during or after exercise. Among them. 34 consecutive patients had no significant coronary stenosis, 26 consecutive patients had CAD QTd were determined before and 1、3、5 minutes after exercise individually in both groups. Results QT dispersion immediately after exercise was significantly greater in the group with significant coronary stenosis than without significant coronary stenosis(65±16ms vs. 40±14ms, P<0. 001). QT dispersion≥60ms immediately after exercise was considered as a positive result, this indicator had a sensitivity of 84. 6% , a specificity of 76. 5% ,and the accuracy of 87. 7% in diagnosing coronary artery stenosis. Conclusion QT dispersion immediately after exercise is an useful indicator in detecting CAD in male patients with negative exercise treadmill test.