胎儿期Ⅰ°房室传导阻滞的诊断性研究分析

目的：选择较理想的指标及临界值点用于筛查胎儿Ⅰ°房室传导阻滞。方法：对62例晚孕孕妇（均大于38周），进行组织多普勒成像（TDI）检测，记录Aa-IV（心房收缩期起点至等容收缩期起点的时间间隔）及Aa-Sa（心房收缩期起点至心室收缩射血期起点的时间间隔），作为胎儿房室传导时间的评价指标。出生后一周内行新生儿心电图检查，测量PR间期。应用直线回归分析，比较Aa-IV、Aa-Sa与PR测值的相关性。绘制受试者工作特征曲线（ROC曲线），分析比较Aa-IV、Aa-Sa的诊断准确性。结果：Aa-IV与PR的相关性更好。ROC曲线显示Aa-IV具有中等诊断意义；Aa-Sa诊断价值较低。根据敏感度及特异度分析，认为Aa-IV≥93.7 ms可作为筛查胎儿Ⅰ°房室传导阻滞的最佳临界值。结论：Aa-IV更适用于胎儿Ⅰ°房室传导阻滞的诊断，筛查胎儿Ⅰ°房室传导阻滞的最佳临界值为Aa-IV≥93.7 ms。

Diagnostic study of fetal first degree atrioventricular block by tissue Doppler imaging

Objective： To confirm the suitable index and critical value in diagnosing the fetal first degree atrioventricular block. Methods： Sixty-two pregnant women in third trimester （≥38 week） of our out-patient clinic were erolled. TDI-derived AV intervals were measured as the intervals from atrial contraction（Aa） to isovolumie contraction（Ⅳ） and from Aa to ventricu-lar systole（Sa）. Their neonatal ECG were performed and the correlation between the neonatal PR intervals and fetal TDI values was analysed by linear regression. Receiver operator characteristic（ROC） curve was established to compare the diagnostic value of Aa-Ⅳ and Aa-Sa and to determine the most suitable critical value to screen the fetal first degree atrioventricular block. Results： Aa-Ⅳ correlated significantly better with neonatal PR intervals than did Aa-Sa. The ROC showed secondary diag- nostic value of Aa-Ⅳ and only little diagnostic value of Aa-Sa. The point （Aa-Ⅳ=93.7 ms） of Aa-Ⅳ curve with sensitivity 100% and specificity 51%, was confirm to screen the first degree atrioventrieular block. Conclutions： TDI-derived Aa-Ⅳ can assess the fetal atrioventricular time interval more accurately than did Aa-Sa. The point （Aa-Ⅳ=93.7 ms） should be used as the critical value to screen the fetal first degree atrioventricular block.