Atrioventricular block in an infant with an atrioventricular septal aneurysm.

A case of atrioventricular (AV) septal aneurysm presenting in late fetal life with AV block is reported. In the neonatal period, second-degree AV block occurred, which progressed during infancy to complete block. This report includes ante- and postnatal echocardiograms demonstrating the anatomy. Only three other reports of AV septal aneurysm are found in the literature, none of which describe heart rhythm disturbance.