Screening and echocardiographic diagnosis of arrhythmias and congenital heart diseases in the fetus

Purpose: To analyze the results of a screening and diagnostic program of arrhythmias and congenital heart disease in a reference hospital and the relevance of early diagnosis in the fetal and neonate evolution. Method: Cardiac evaluation of 1159 fetuses was done in two different levels. Level I: by morphological ultrasound examination with the objective to detect the existence of either arrhythmias or structural cardiac malformations. Level II: by fetal echocardiography to establish the differential diagnosis. The results of level I in the arrhythmia group were compared with those of level II, and in the group with malformations the results of both levels were confronted with the neonate echocardiogram or necropsy. The kappa index was calculated to evaluate the concordance between the two levels. Results: All detected arrhythmias in level I were confirmed in level II, there were no false negative cases and five patients with severe arrhythmia required pharmacological therapy. The diagnosis of structural malformation by level I had sensitivity of 72% and specificity of 98% and there were 28% of false-positive cases. In level II, the sensitivity and specificity of the diagnosis of congenital heart disease were 100 and 99%, respectively. The kappa index was 57% and indicated a moderate degree of concordance between the two levels. Fifty-one percent of the fetuses with diagnosis of cardiac malformations required pharmacological or invasive intervention immediately after birth. Conclusion: Morphological ultrasound examination is a important tool in the screening of arrhythmias and congenital heart defects during fetal life. The sensitivity and specificity of the fetal echocardiogram were very high and the early diagnosis made it possible to treat the fetus with severe cardiac disease either during pregnancy or immediately after birth.