Effective prevention of atrial fibrillation by continuous atrial overdrivepacing after coronary artery bypass surgery

OBJECTIVES The present study was aimed to evaluate the efficacy of a specif ic algorithm with continuous atrial dynamic overdrive pacing to prevent atr ial fibrillation (AF) after coronary artery bypass graft (CABG) surgery. BACKGROUND Atrial fibrillation occurs in 30% to 40% of patients after cardi ac surgery with a peak incidence on the second day. It still represents a c hallenge for postoperative prevention and treatment and may have medical an d cost implications. METHODS Ninety-six consecutive patients undergoing CABG for severe coronary artery disease and in sinus rhythm without antiarrhythmic therapy on the s econd postoperative day were randomized to have or not 24 h of atrial pacin g through temporary epicardial wires using a permanent dynamic overdrive al gorithm. Holter ECCs recorded the same day in both groups were analyzed to detect AF occurrence. RESULTS No difference was observed in baseline data between the two study g roups, particularly for age, male gender, history of AF, ventricular functi on, severity of coronary artery disease, preoperative beta-adrenergic block ing agent therapy or P-wave duration. The incidence of AF was significantly lower (p = 0.036) in the paced group (10%) compared with control subjects (27%). Multivariate analysis showed AF incidence to increase with age (p = 0.051) but not in patients with pacing (p = 0.078). It decreased with a bet ter left ventricular ejection fraction only in conjunction with atrial paci ng (p = 0.018). CONCLUSIONS We conclude that continuous atrial pacing with an algorithm for dynamic overdrive reduces significantly incidence of AF the second day aft er CABG surgery, particularly in patients with preserved left ventricular f unction. (C) 2000 by the American College of Cardiology.