Troubleshooting Implantable Cardioverter Defibrillator System Malfunctions: The Role of Impedance Measurements

High impedance measurements may be used to troubleshoot ICD system malfunction. In four different cases a defective system was identified or confirmed by an abnormal impedance: two secondary to lead fractures, one to an adapter faulty connection, and one to a hose set-screw connection. This led to further diagnostic procedures that ultimately localized the difficulty. Though the problems with ICD may be of diverse origins, routine use of impedance measurement for the troubleshooting of these systems may serve as an early sign of malfunction and would point the need for further investigation.