Epicardial pacemaker lead-induced ventricular tachycardia.

A 9-year-old boy with a permanent epicardial screw-type ventricular pacemaker lead (VVI mode), fitted due to a complete atrioventricular block after ventricular septal defect closure at 5 months of age, showed ventricular tachycardia during maximal exercise testing. The pacemaker lead was found to have fractured at 30 mm from the tip, and the screw tip penetrated the right ventricular cavity. Pace mapping at the anterior free wall of the right ventricle detected a 12/12 matched ventricular tachycardia focus around the site of penetration. The fractured lead was extracted under cardiopulmonary bypass support and the lead insertion site cryoablated. Subsequently, ventricular tachycardia was not induced during maximal exercise testing.