NORTH-AMERICAN VASOVAGAL PACEMAKER STUDY - STUDY DESIGN AND ORGANIZATION

The North American Vasovagal Pacemaker Study is an ongoing multicenter randomized, clinical trial that assesses She efficacy of dual chamber pacing utilizing rate drop sensing in patients with frequent syncopal spells. Patients are eligible if they have had at least six syncopal spells and a positive tilt table test, or a recurrence of syncope with in 6 months of a positive tilt test. The tilt table test must have pro voked a relative bradycardia. Patients are randomized to receive a Med tronic Thera DR with rate drop sensing, or to continue on their usual therapy. All patients complete a log of their presyncopal and syncopal spells daily, and are contacted every 2 months. The primary outcome m easure is the time to the first recurrence of syncope. The goal of the main study is to recruit 284 patients in 3 years with a final fourth year of follow-up: this will result in an 80% chance of detecting a 30 % reduction in the risk of syncope. A pilot study is under way with th e aim to recruit 60 patients over a period of 2 years with a final thi rd year of follow-up, Recruitment began in July 1995 and 47 patients h ave been enrolled to date.