Random internal component failure of an implantable cardioverter defibrillator.

Internal component failure of the Implantable Cardioverter Defibrillators (ICD) is a rare complication, which can have a potentially catastrophic outcome. We describe a patient with random component failure, which occurred due to electrical overstress damage to the high voltage hybrid as a result of inappropriate arcing, as detected by the manufacturer. This in turn damaged other components in the device. This secondary damage caused the device to reset, emitting a constant tone. A high current state was created, thereby depleting the battery prematurely. The problem was promptly detected and rectified by ICD generator replacement.