心脏变时指数对冠心病的诊断

目的 评价心脏变时指数对冠心病的诊断价值.方法 对疑诊冠心痛的162例患者,先常规行运动平板试验,测定运动试验过程中心电图ST段变化值和心脏变时指数.平板运动试验后3周内行冠状动脉造影检查,以冠状动脉造影结果作为诊断冠心痛的标准.结果 心脏变时指数标准与传统ST段标准诊断冠心痛的敏感性为70.1%和60.9%(P<0.05),特异性为84.0%和73.3%(P<0.05),准确性为76.5%和66.7%(P<0.05).心脏变时指数指标与冠状动脉造影一致性检验的Kappa值为0.534(>0.4).心脏变时指数与冠状动脉病变支数相关,心脏变时指数平均值从0支冠状动脉病变的0.88±0.09,逐渐下降到3支冠状动脉病变的0.68±0.06(P<0.01).相关性分析显示心脏变时指数阳性与右冠状动脉病变的相关性更好.结论 心脏变时指数可能成为诊断冠心病的一项阳性指标,其敏感性、特异性和准确性均高于ST段标准的普通运动心电图试验.

Value of chronotropic index in identifying coronary artery disease

Objective To assess the diagnostic value of chronotropic index in identifying coronary artery disease (CAD). Methods One hundred and sixty two patients with suspected CAD were referred for a routine treadmill exercise electrocardiogram and subsequently underwent selective coronary angiography within 3 weeks. The magnitude of ST segment depression and chronotropic index were measured by a computerized ECG system. CAD was defined by coronary angiography. Results In detecting CAD, the sensitivity was 70. 1% versus 60.9% (P< 0.05) ,the specificity was 84.0% versus 73.3% (P<0.05), and the accuracy was 76.5% versus 66.7% (P< 0.05) by chronotropic index and standard electrocardiographic test criteria. The value of Kappa statistic for chrono-tropic index consistency in our experiment was 0.534(>0.4). The number of diseased vessels was correlated with the mean value of chronotropic index. The chronotropic index decreased from 0.88±0.09 in patients without coro-nary disease to 0.68±0.06 in those with 3 vessels involved (P<0.01). A more closed relationship was found be-tween chronotropic index and lesion in the fight coronary artery. Conclusions Chronotropic index is possibly a valu-able positive index for the diagnosis of CAD. The sensitivity,specificity and accuracy of chronotropic index are signif-icandy higher than those of standard electrocardiographic test criteria in identifying CAD.