心脏轴测定在胎儿先天性心脏病产前超声诊断中的临床意义

Clinical Significance of Cardiac Axis Determination in Prenatal Echocardiographic Diagnosis of Fetal Congenital Heart Disease

目的探讨超声心动图测定心脏轴变化在胎儿先天性心脏病（先心病）产前诊断中的临床意义。方法应用Ａｃｕｓｏｎ１２８×Ｐ／１０彩色多普勒超声诊断仪检查５１８例胎龄１８～４０周的先心病高危胎儿和９０例正常胎儿，在心脏超声四腔观基础上测定胎儿心脏轴，并从多切面观察胎儿心内结构，以确定胎儿有无先心病。结果正常胎儿心脏轴为（４４．８±１０．３）度，先心病胎儿心脏轴为（５８．１±１５．７）度，两者比较，差异有显著性（Ｐ＜０．０１）。单纯四腔观检测胎儿先心病的敏感性为６８．５％，应用心脏超声四腔观加心脏轴测定检测胎儿先心病的敏感性为９１．４％，两者比较，差异有显著性（Ｐ＜０．０５）；５１８例先心病高危胎儿中，产前超声正确诊断先心病３４例，假阳性１例，假阴性１例。结论正常胎儿心脏轴范围２０～７５度，如心脏轴＞７５度，应高度怀疑胎儿先心病；心脏轴测定在胎儿先心病筛查中具有重要作用，可作为一种常规测量指标。

Objective To investigate the clinical significance of cardiac axis determined by echocardiography in prenatal diagnosis of fetal congenital heart disease (CHD). Methods 518 high risk fetuses for CHD were and 90 normal fetuses were examined by echocardiography. Cardiac axis was measured on four chamber view and fetal cardic anatomical structure was examined in multiple views to determine CHD. Results The 35 fetuses with CHD diagnosed by prenatal echocardiography. There is significant difference of caidiac axis between CHD group (58.1±15.7 degree) and normal group (44.8±10.3 degree, P <0.01). Sensitivity of CHD diagnosis using four chamber view alone is 68.5%, it will be elevated to 91.4% by combination of four chamber view and cardiac axis determination ( P <0.05). Conclusion Cardiac axis play an improtant role in fetal echocardiographic screening for CHD and it should be measured routinely as part of the four chamber view of the fetal heart. The normal range of fetal cardiac axis is 20 to 75 degree. If it was more than 75 degree, the CHD should be suspected.