Selective Use of Amiodarone and Early Cardioversion for Postoperative Atrial Fibrillation

Background Postoperative atrial fibrillation (AF) occurs in 20%–40% of patients undergoing open-heart surgery. Numerous pharmacological and electrical therapies have been used as a prophylaxis to prevent this dysrhythmia. The purpose of this study was to examine the selective use of amiodarone and early cardioversion (CVN) postoperatively to restore normal sinus rhythm (NSR). Methods A retrospective nonrandomized review of patients who received amiodarone and early electrical CVN (study group) for postoperative AF after coronary artery bypass grafting (CABG) were compared with patients who received nonamiodarone therapies (control group). The study group received 150 mg of amiodarone bolus intravenously and thereafter received an infusion of 1 g over a 24-hour period. If NSR was established within 24 hours, then the intravenous (IV) infusion was continued for another 24 hours with concomitant oral amiodarone overlap. If NSR was not established within 24 hours, then external electrical CVN was performed. After 48 hours, the IV infusion was discontinued and the oral regimen maintained through discharge. Control group patients received either combination digoxin and procainamide or diltiazem. Postoperative β-blocker administration was instituted in all patients. Results Six-hundred forty consecutive CABG patients were examined between July 1995 and June 2003. Postoperative AF developed in 160 of these patients (25%). One-hundred patients constituted the study group and 60 patients represented the control group. Restoration of NSR within 24 and 48 hours occurred in 79 (79%) and 90 patients (90%) for the study group, respectively, compared with 38 (64%) and 44 patients (73%) for the control group, respectively. The presence of NSR at discharge was achieved in 98 study patients (98%) and 50 control patients (83%). The length of stay (LOS) for the study and control patients was 7.4 and 9.1 days, respectively. There was no mortality in either group. Conclusions Amiodarone and early CVN was more effective than nonamiodarone therapies with regard to restoring NSR for patients in whom AF developed after elective CABG. A trend toward a decrease in LOS was observed in the study group, but was not statistically significant. The overall LOS using amiodarone therapy with early CVN was similar to postoperative AF for patients in whom the condition did not develop.