Hypoplastic left heart syndrome with restrictive atrial septum and advanced heart block documented with a novel fetal electrocardiographic monitor.

Hypoplastic left ventricle with congenital heart block has been reported previously in a fetus with concurrent left atrial isomerism and levo-transposition of the great arteries. We present the unusual case of an infant diagnosed in utero with hypoplastic left heart syndrome, a restrictive atrial septum and advanced heart block but with D-looping of the ventricles and no atrial isomerism. In addition, fetal heart rhythm was documented with the assistance of a new fetal electrocardiographic monitor.