Atrial Pacing in the Prevention of Paroxysmal Atrial Fibrillation: First Results of a New Combined Algorithm

UNLABELLED: Pacing algorithms for prevention of atrial tachyarrhythmia (AT) are under clinical evaluation. The present study prospectively evaluated the efficacy of three simultaneously active algorithms for AT prevention and aimed at identifying patients in whom atrial preventive pacing (APP) may be particularly successful. METHODS: In 31 patients with conventional pacing indications and paroxysmal AT, a DDDRP pacing system was implanted, which stores 35 AT episodes with atrial electrograms and marker annotations. Counters and stored AT episodes were retrieved 30 days after implant. APP algorithms (atrial preference pacing, atrial rate stabilization, postmode switching overdrive) were activated. Counters and stored AT episodes were again retrieved 60 days later. The number and duration of AT episodes was measured. Several clinical variables were examined with respect to their ability to identify candidates for APP. RESULTS: During APP, the mean number of AT episodes/patient/day decreased from 7.67 to 1.68 (P = 0.04). However, time in AT was not significantly reduced (9.45% versus 10.41%). APP decreased the number of episodes/day in 11 patients and increased it in 9 patients. No clinical parameters predicting APP success was identified. CONCLUSIONS: APP using three algorithms significantly reduced the mean number of AT episodes/patient/day. However, the time during which patients were in AT was not reduced. No clinical variable predicted the success or failure of APP.