A Randomized Controlled Clinical Trial Comparing Ventricular Fibrillation Detection Time Between Two Transvenous Defibrillator Models

The Ventak AV is an implantable cardioverter defibrillator with dual chamber pacing capability. Features include detection and treatment of ventricular arrhythmias, detection of atrial arrhythmias, as well as dual chamber pacing. The objective of the investigation was to verify the efficacy of the Ventak AV in detecting ventricular fibrillation in the presence of dual chamber pacing. Thirty-three patients, who were to receive an implantable defibrillator were randomized (1:1) in a paired comparison study to the Ventak AV (study device) and the Ventak Mini (control) during defibrillation threshold testing. In order to create a "worst case scenario" for sensing of ventricular fibrillation, pacing was performed at high lower rate limit values (Ventak AV DDD pacing at 150/min, Ventak Mini at VVI 100/min). Ventricularfibrillation was induced and the randomized device was allowed to detect and treat the arrhythmia. This test was repeated for each patient using the alternate device in a randomized order, such that all patients were tested with both devices. The mean ventricular fibrillation detection time for the Ventak AV was 2.0+/-0.11 seconds and for the control device the detection time was 1.8+/-0.11 seconds (P = 0.26). Appropriate tachyarrhythmia therapy decision was documented in all episodes for both devices. The study patient population demonstrated equivalent ventricular fibrillation detection time between the Ventak AV and the Ventak Mini. The Ventak AV demonstrated effectiveness in detecting ventricular fibrillation in the presence of high rate dual chamber pacing.