Is the pace/sense conductor related to a high voltage short circuit in a dual coil ICD system? An experimental study

Abstract

Background: We carried out a bench study of implantable cardioverter-defibrillator (ICD) performance in order to investigate whether the right ventricular (RV) ring contributes to the occurrence of a high-voltage (HV) short circuit. Methods: A polycarbonate water bath with 0.18% saline was prepared. An ICD lead was connected to an ICD device and both were placed into the water bath. The impedance of each electrode and coil was measured. In the first experiment, the RV ring was shorted to the RV coil using an alligator clip. The impedance of each electrode and coil at shorting was measured. A maximum energy defibrillation shock was delivered. The therapy log confirmed the HV short circuit and the delivery conditions. In the second experiment, a short circuit was established between the RV ring and the superior vena cava coil and a similar procedure was followed. Results: No HV short circuit was observed in either experiment. Scheduled shock energies were delivered without problems. Some changes in pace–sense impedance or coil impedance were observed, but they remained within the normal range. Conclusions: The RV ring conductor is not related to HV short circuits, even if the RV ring and/or RV ring conductor is placed in contact with HV electrodes.

Keywords

• Implantable cardioverter-defibrillator
• Lead failure
• Short circuit
• Pacing
• Sensing