A male child, 18 months old, with interrupted aortic arch, ventricular septal defect, postoperative complete heart block and an epicardial DDD pacemaker since the age of nine months, was admitted to our department because of episodes of syncope. At first the episodes were considered as epilepsy and the child was given antiepileptic drugs. Twenty-four-hour ambulatory electrocardiographic monitoring revealed dysfunction of the pacemaker due to exit block in the ventricular lead, while the atrial lead was functioning properly. The young patient was treated by preservation of the epicardial atrial lead and implantation of the ventricular lead via the transvenous route. The ventricular lead was then connected through a subcutaneous channel to the pulse generator in an abdominal pocket.