Late electrophysiology complications after surgical repair of D-transposition of great arteries.

Late-onset atrioventricular (AV) block is an infrequent but life-threatening complication after surgical repair of congenital heart disease. We present a rare case of late-onset AV block in an adolescent who developed high-grade AV block long after undergoing an arterial switch operation and ventricular septal defect (VSD) patch closure. The patient had a significant past medical history of ventricular ectopy detected two and a half years before her presentation with AV block, for which an ablation of a slow ventricular tachycardia was performed close to the superior border of the VSD patch. On follow-up, a few years later, she was noted to have a high-grade AV block during stress testing and an electrophysiology study and underwent a pacemaker implantation. AV heart block is a life-threatening complication that needs to be monitored for in all patients with a history of a VSD repair.