平板运动试验中IQTd诊断冠心病的价值

Diagnostic value of QT dispersion adjusted by heart rate for coronary artery disease in exercise treadmill test

目的 评价用心率调整QTd指标 (IQTd)在平板运动试验中对冠心病的诊断价值。方法 4 3例患者在冠状动脉造影前行平板运动试验 (ETT) ,测量其运动前、运动中与ST段下移最大时或最大负荷心率时 (无ST段下移者 )QTd、校正QTd(QTdr、QTcdr、QTdp、QTcdp) ,分别计算IQTd和IQTcd。ETT后 1周内行冠状动脉造影 (CAG) ,根据CAG结果分为冠心病 (CAD)组 2 3例和冠状动脉正常 (NCAD)组 2 0例。结果 运动前的QTdr和QTc dr在CAD与NCAD组间无显著差别。在冠状动脉正常组 ,运动过程QTdp和QTcdp无显著增加 ,而在冠心病组QTdp和QTcdp有显著性增加 (P <0 0 0 1)。在运动过程中 ,QTdp、QTcdp、IQTd、IQTcd在CAD与NCAD组间有明显差异。在NCAD组QTdp、QTcdp、IQTd、IQTcd95 %上限值分别为 74ms、86ms、0 .17ms/bpm和0 2ms/bpm。用其界值作为诊断标准 ,其特异性显著高于ST段压低 ,IQTd和IQTcd的敏感性和准确性显著高于ST压低 (P <0 0 5 )。结论 提示IQTd、IQTcd可作为平板运动试验中诊断冠心病敏感。

Objectives To evaluate the diagnostic Value of the change of QT dispersion (QTd) abjusted by heart rated for coronary artery disease (CAD) in exercise treadmill test (ETT). Methods ETTs were performed in 43 cases before coronary angiography. QTd. Correct QTd(QTcd) were measured before ETT and during ETT when ST segments depression was most or maximal heart rate was achieved while ST segments didn't depress in 23 cases of coronary artery disease (CAD) and 20 cases of non-CAD confirmed by coronary angiography. IQTd, IQTcd were calculated respectively. Results Before exercise, QTd and QTcd were no significant differences between CAD and NCAD group. QTd, QTcd were no significantly increased during exercise in NCAD group and were significantly increased in CAD group during exercise ( P<0.001 ). QTd, QTcd, IQTd, IQTcd were significant differences between CAD group and NCAD group during exercise. The 95% superior limit values was 74 ms, 86 ms, 0.17 ms/bpm and 0 2 ms/bpm in NCAD group. Using the superior limit values as diagnostic criteria, specificity of the four variables was significantly higher than that of ST depression ( P<0.05 ). Sensitivity and accuracy of IQTd and IQTcd were significantly than that of ST depression ( P<0.05 ). Conclusions The study suggest that IQTd and IQTcd could be used as a sensitive? accuracy and specific index for the diagnosis of CAD in ETT.