Sensing Lead Insulation Defect Resulting in a Damage of the ICD Pulse Generator Case

Eight months after ICD implantation with an electrically active case the patient presented with ICD system sensing failure. Upon re-operation, we found an insulation defect of the proximal sensing lead and the generator case showed arc marks suggesting a short circuit between the sensing lead and case. the generator was replaced, the original sensing lead insulated, and a new sensing lead inserted. Bench testing of the explanted generator showed a damaged internal circuitry. Proximal lead insulation defects combined with electrically active cases may result in damage of the case. The potential damage of internal circuitry warrants generator replacement.