Biventricular pacing in an infant with noncompaction of the ventricular myocardium, congenital AV block, and prolonged QT interval.

We describe the case of a newborn with isolated noncompaction of the ventricular myocardium, congenital atrioventricular block, and prolonged QT, who developed a dilated cardiomyopathy after 4 months of right ventricular permanent pacing. The implanted system was upgraded to biventricular pacing. Resynchronization therapy was associated with normalized septal motion and shortening of the interventricular delay and, within 2 months after initiation, resulted in markedly improved left ventricular ejection fraction and reduced ventricular volume.