T离散度诊断冠心病心肌缺血的价值

为探讨QT离散度 (QTd)诊断冠心病心肌缺血的价值 ,记录 5 1例冠心病胸痛发作时 ,发作前、后的 12导联同步体表ECG ,测定并计算QTd、校正的QTd(QTcd)及ST段变化 ,判断有关指标诊断冠心病心肌缺血的灵敏性和特异性。结果 :心绞痛 (AP)发作时QTd及ST段改变显著高于胸痛发作前、后的QTd及ST改变 (分别为 80 .1± 2 2 .4vs4 5 .8± 16 .2 ,4 7.8± 17.0 0ms ,P <0 .0 5 ;0 .12± 0 .0 0 8vs 0 .0 3± 0 .0 0 9,0 .0 2± 0 .0 0 7mV)。QTd增大至≥ 80ms、QTd增加≥ 5 0 %、QTd增加≥ 5 0 %兼≥ 80ms、ST段压低或抬高≥ 0 .1mV诊断心肌缺血的灵敏性分别为 86 .2 7%、80 .39%、78.4 3%、5 2 .94 % ;特异性分别为 90 .70 %、79.0 7%、10 0 %、88.37%。结论 :AP发作时QTd显著增大 ,QTd的有关定量指标可作为诊断冠心病心肌缺血的良好指标 ,其中以QTd增加≥ 5 0 %兼≥ 80ms特异性最好。

The Value of QT Dispersion in Diagnosing Angina Pectoris Myocardial Ischmia in Patients With Coronary Artery Disease.

In order to evaluate the value of QT dispersion(QTd) in diagnosing myocardial ischmia,the standard 12 lead electrocardiogram was recorded in 51 patients with comfirmed by coronary angiography before,at the onset and within 30 minutes of the chest pains.The QTd, corrected QTd (QTcd) and ST segment changes were measured.Result:The QTd, the QTcd and the ST segment depression were markedly increased during the onset of chest pains than that before and after chest pains in the patients with AP ( P <0.05 or <0.01). The sensibility of diagnosing myocardial ischemia was 86.27%,80.39%,78.43%,52.94% respectively by QTd ≥80 ms,QTd increasing by 50%,QTd increasing by 50% and ≥80 ms,ST segment depressing or elevating ≥0.1 mV.The specificity was 90.7%, 90.7%, 100%,88.37% respectively.Conclusion: The QTd was increased significantly during the onset of chest pains in patients with angina pectoris.QTd increasing by≥50% and reaching 80 ms or above could be used as index for the diagnosing of myocardial ischmia.