Staged pacing therapy for congenital complete heart block in premature infants

Abstract

Although congenital complete heart block (CHB) is usually well tolerated by the developing fetus, it may occasionally result in hydrops fetalis 1,2 with a significant risk of fetal or neonatal death. 3 The treatment of the fetus with CHB and hydrops remains a difficult problem. Attempted pharmacologic therapies have included β-adrenergic agonists, 3 corticosteroids, 4 and intravenous immunoglobulins, 5 none of which have been widely effective. One report of transuterine transthoracic fetal ventricular pacing was not successful in bringing the fetus to term. 6 Although animal studies of fetal permanent pacemaker systems implantation are under way, 7 this approach has not been used in humans. Because currently available in utero therapy is unable to halt the progression of fetal hydrops, one must usually resort to early delivery and extrauterine pacing of a compromised (and often premature) neonate. On occasion, these infants are too small to accept immediate implantation of a permanent pacing system, and use of temporary transvenous pacing wires carries the risk of cardiac perforation and venous thrombosis in the very small child. This report describes an alternate pacing strategy in 2 premature infants with CHB, involving the use of temporary epicardial pacing wires to bridge the interval until the permanent pacemaker can be implanted.