Risk factors for the development of recurrent atrial fibrillation: role of pacing and clinical variables.

Atrial fibrillation recurs in many patients treated with antiarrhythmic therapy to maintain sinus rhythm. From March 1985 to August 1991, 214 patients with recurrent symptomatic chronic or paroxysmal atrial fibrillation for which conventional antiarrhythmic agents had failed were treated with propafenone or sotalol. Baseline demographic data including the presence of pacing therapy were collected. Life-table estimates of the duration of freedom from atrial fibrillation were constructed on the basis of pacemaker status. Of 214 patients, 26 (12.1%) had pacing therapy. Patients with dual-chamber pacing were more likely to remain in sinus rhythm at 6 months (80%) than were patients with ventricular pacing (40%) or patients without pacing therapy (55%) (p = 0.002). A Cox univariate regression analysis demonstrated that dual-chamber pacing in contrast to ventricular pacing or no pacing was associated with a lower risk of recurrent atrial fibrillation. Clinical parameters such as age, gender, left atrial size, fibrillation pattern, drug assignment, ejection fraction, and underlying cardiac disease did not alter the risk of recurrent atrial fibrillation. Dual-chamber pacing was associated with a decreased likelihood of recurrent atrial fibrillation even after adjustment for other clinical covariates in a multivariate model (p = 0.04). In patients with recurrent atrial fibrillation treated with propafenone or sotalol, dual-chamber pacing improved maintenance of sinus rhythm.