ΔQTd/ΔHR指标评价食管心房调搏负荷试验对冠心病的诊断价值

Diagnostic value of QT dispersion adjusted by heart rate for coronary artery disease in transesophageal atrial pacing stress test

目的 :研究经食管心房调搏负荷试验 ( TEAPT)中 ,心率 ( HR)调整 QT离散度 ( QTd)变化指标对冠心病 ( CHD)的诊断价值。方法 :5 0例在冠状动脉 (冠脉 )造影前后 1周内作 TEAPT,测定静息及负荷峰值的 QTd、校正 QTcd( QTdr、QTcdr、QTdp、QTcdp)计算 ΔQTd/ Δ HR指数及 Δ QTcd/ Δ HR指数 ( IQTd、IQTcd)并比较此各项参数及 ST标准的诊断效能。结果 :CHD组 ( 2 7例 )的 QTdp、QTcdp、IQTd、IQTcd值均显著大于冠脉正常( NCHD)组 ( 2 3例 ) ( t≥ 4 .5 9,P <0 .0 0 1) ,4个参数在 NCHD组的 95 %上限值分别为 60 m s、95 m s、0 .2 4 m s/(次· m in)、0 .5 8ms/ (次· min) ,诊断 CHD的特异性均显著大于 ST压低标准 ( P <0 .0 5 ) ,IQTd、IQTcd的敏感性和准确性显著高于 QTcdp及 ST压低标准 ( P <0 .0 5～ 0 .0 1)。结论 :IQTd、IQTcd是 TEAPT诊断

Objective: To demonstrate our hypothesis that the change of QT dispersion (QTd) adjusted by heart rate could increase diagnostic value for coronary artery disease in transesophageal atrial pacing test (TEAPT).Method: TEAPTs were performed in 50 cases before or after coronary arteriography within 1 week. QTd during rest (QTdr) and load peak (QTdp), correct QTdr(QTcdr), correct QTdp(QTcdp) and ΔQTd/ΔHR index(IQTd) and ΔQTcd/ΔHR index (IQTcd) were measured and calculated respectively. Diagnostic values of the variables were compared.Result: Twenty seven cases (CHD group)had coronary artery disease and 23 cases had no significant stenosis of coronary artery (NCHD group). QTdp, QTcdp, IQTd, IQTcd in CHD group were more significantly increased than those in NCHD group (t≥ 4.59 , P< 0.001 ). The 95% superior limit values was 60 ms, 95 ms, 0.24 ms/bpm and 0.58 ms/bpm respectively in NCHD group. Using the superior limit values as diagnostic criteria, we found that specificity of the 4 variables was significantly higher than that of ST depressions (P< 0.05 ). Sensitivity and accuracy of IQTd and IQTcd were significantly higher than those of QTcdp and ST depression (P< 0.05 ～ 0.01 ).Conclusion: IQTd and IQTcd are new accurate indexes in diagnosing CHD.