PP-176 - A Fully Malfunctioning Implantable Cardioverter - Defibrillator Device

Abstract

A 50-year-old male with 2 mechanical heart valves and cardiomyopathy underwent a single electrode dual coil (Durata™, St. Jude Medical) implantable cardioverter-defibrillator (ICD) (Current™ + VR, St. Jude Medical) implantation in 2014. No device interrogation although the device activated the patient notifier for many times was performed due to patient's non-compliance until worsening of heart failure and hospitalization. Device interrogation showed too high ventricular lead impedance (>3000 Ω), too low high voltage (HV) lead impedance (<10 Ω), inconvenient sensing values with no activity in ventricular sense amplitude channel (the only channel configured) mostly, and no pacing capture although the device showed continuous ventricular pseudo-pacing in the ventricular sense amplitude and marker channels at predefined back-up level of 40 bpm (Figure 1A). Numerous event records demonstrated artefacts with variable sensing signals including very high counts and silences in ventricular sensing amplitude channel and fibrillation markers in marker channel mostly ended spontaneously and, sometimes resulted in capacitor charging with premature decharging (Figure 1B). Alerts box included 255 possible HV circuit damage detections, no successful charge since first detection, aborted shocks due to a possible HV lead issue, possible HV lead issue, ventricular lead impedance > upper limit, HV lead impedance > upper limit, and delivered patient notifiers. The postero-anterior chest X-ray showed the fractured lead in the pectoral region. Before replacing both the electrode and the generator fluoroscopy of the entire system demonstrated fractured segments in detail without additional gross abnormality (Figure 1C).