Benefits of Dual-Chamber Defibrillator Pacing

A new study shows that implantable cardioverter defibrillator (ICD) dual-chamber pacing in combination with proactive reduction of right ventricular (RV) pacing reduces heart failure hospitalization and all causes of mortality.

The Intrinsic RV (Inhibition of Unnecessary RV Pacing with AV Search Hysteresis in ICDs) multi-center trial enrolled 1,530 patients with a current indication for an ICD at 108 centers in the United States, Germany, Italy, and Australia. The primary endpoint was a composite of all-cause mortality and heart-failure hospitalization. Patients in the dual-chamber pacing in combination with arteriovenous (AV) Search Hysteresis (AVSH) programming group experienced 33% fewer deaths and heart-failure hospitalizations compared to single chamber pacing. The results of the study were published in the January 2007 issue of the journal Circulation.

AV Search Hysteresis (AVSH) programming is a proprietary feature of Boston Scientific (Natick, MA, USA) which allows intrinsic AV conduction beyond the programmed AV delay to help minimize ventricular pacing.

"The results of this landmark study are important because dual-chamber ICD programming can provide benefits to patients that single-chamber programming may not, such as improved heart function and enhanced arrhythmia detection,” said lead author Brian Olshansky, M.D., a professor of medicine and director of cardiac electrophysiology at the University of Iowa Hospitals and Clinics (Iowa City, USA). "Prior studies have suggested that dual-chamber devices may lead to unnecessary RV pacing, which in some patients may pose safety concerns. This study showed that these perceived safety concerns were not present in the patient arm where dual-chamber pacing with AV Search Hysteresis was used.”



Related Links:
Boston Scientific
University of Iowa Hospitals and Clinics