Congenital atrial flutter.

Two cases of congenital atrial flutter, one of which was documented electrocardiographically before birth, are reported. In both patients sinus rhythm was restored with digoxin treatment; in one patient the transition was preceded by various arrhythmias. No cardiac malformation was found in either case, and no materal disease occurred during pregnancy. Both mothers had received medication during pregnancy, but its role as a causative factor is questionable.