Boston Scientific Corporation reported that the Intrinsic RV investigative team presented results of a clinical trial designed to study unnecessary pacing in recipients of an implantable cardioverter defibrillator (ICD). The trial, Inhibition of Unnecessary Right Ventricular Pacing with AV Search Hysteresis in ICDs (INTRINSIC RV), was designed to advance our understanding of a proprietary feature that minimizes unnecessary right ventricular pacing in patients who received the company's market-released dual-chamber ICD. A dual-chamber ICD can pace and/or sense in the upper and lower chambers of the heart. The results were announced at the Heart Rhythm Society (HRS) annual meeting in Boston.

Intrinsic RV is a multi-centre, randomized trial enrolling more than 1,500 patients at 108 centres in the United States, Germany, Italy and Australia. The trial utilized the company's exclusive AV Search Hysteresis (AVSH) feature, which has been incorporated in all the company's dual-chamber ICDs since June 2000.

Brian Olshansky, director of cardiac electrophysiology at the University of Iowa Hospitals and co-principal investigator of Intrinsic RV commented, "This trial highlights the importance of evidence-based medicine to further the understanding of advanced-feature medical devices, because Intrinsic RV actually refutes the notion that dual-chamber ICD programming poses an inherent safety risk. In fact, by using AV Search Hysteresis, outcomes with dual-chamber programming performed as well as, if not better, than single-chamber programming."