992-109 Prolonged Redetection of Ventricular Fibrillation with an Integrated Lead System

Integrated defibrillator leads incorporate both sensing electrodes and a shocking coil in the ventricle. Although this facilitates lead system placement, sensing may be impaired because of the high energy electric fields close to the sensing electrodes. To evaluate this, we prospectively compared sensing in 55 patients (pts) who had received either a dedicated sensing lead without ventricular coils (CPI BT-10, BT) or an integrated lead (CPI Endotak, ET). VF was induced with ramp pacing from a temporary pacing catheter and sensing was automatically performed by the defibrillator (Ventak 1600). Redetection was assessed from a failed first shock just below defibrillation threshold. Mean patient age (64 yrs) and mean LVEF (33%) did not significantly differ between the two groups. Results are shown below (mean±SD).Type of leadNDetect time (sec)Redect time (sec)*BT323.2±1.83.6±2.6ET232.9±3.85.4±3.5*P<0.05 between the two types of leadsProlonged redection (>6 sec) was found in 26% of pts with ET compared to 6% in pts with BT (P<0.05). Redection following a sub-therapeutic shock is longer with integrated ICD lead (ET) utilizing defibrillation coil as part of the sensing circuit. The clinical significance of this finding needs to be assesse