Italian Multicenter Study on a Single Lead VDD Pacing System Using a Narrow Atrial Dipole Spacing

Since November 1988, 514 patients with advanced atrioventricular (AV) block and normal sinoatrial function have received the single lead VDD pacing system Twinal 30 Lem/CCS in 30 Italian centers. At implantation, particular attention was paid to the correct positioning of the atrial dipole in the mid‐ to mid‐high right atrium and to the atrial electrogram characteristics. The follow‐up included a chest X ray, to be performed before discharge of the patient from the hospital, telemetric evaluations of the endoatrial potential, provocative tests for interferences by myopotentials, 24‐hour ambulatory EGG recordings, and where possible, exercise stress tests. The mean follow‐up duration was 15.2 months, ranging from 1 to 42 months. A very low percentage of chronic atrial fibrillation, loss of atrial sensing, and system replacement was reported, most of the patients (93.5%) being paced in VDD mode. All investigations indicated an excellent overall system performance, stable AV synchrony, and infrequent myopotential interference, and a low complication rate throughout the follow‐up period.