Nonsurgically-acquired complete atrioventricular block in endocardial cushion defect.

Complete atrioventricular heart block (CAVB) most commonly occurs as a complication of cardiac surgery. We report the development of CAVB in an 8-year-old girl with endocardial cushion defect (ECD) who had not undergone a cardiac operation. Although this is the first report of acquired non-surgical CAVB in a child with ECD, we believe that the development of CAVB in patients with unoperated ECD occurs more commonly than is usually realized. An increased awareness of this possibility will allow expedient diagnosis, which is essential to proper treatment. In most cases, the implantation of a permanent ventricular pacemaker will alleviate congestive heart failure or prevent sudden death.