Esmolol versus diltiazem in the treatment of postoperative atrial fibrillation/atrial flutter after open heart surgery

Background Supraventricular tachyarrhythmias are common after open heart su rgery. Possible causative factors for these arrhythmias include operative t rauma, atrial ischemia, electrolyte imbalances, pericardial irritation, and excess catecholamines. Two agents commonly used to control ventricular rat e in atrial fibrillation or atrial flutter (AF/AFL) are beta-blockers and c alcium channel blockers. Methods and Results This randomized study was designed to compare the safet y and efficacy of intravenous diltiazem versus intravenous esmolol in patie nts with postoperative AF/AFL after coronary bypass surgery and/or valve re placement surgery. A comparative cost analysis was also performed. Thirty p atients received either esmolol (n = 15) or diltiazem (n = 15) for AF/AFL. During the first 6 hours of treatment, 66.6% of esmolol-treated patients co nverted to sinus rhythm compared with 13.3% of the diltiazem-treated patien ts (P < .05). At 24 hours, 66.6% of the diltiazem group converted to SR com pared with 80% of the esmolol group (not significant). Drug-induced side ef fects, time to rate control (<90 beats/min), number of patients requiring c ardioversion, and length of hospitalization were similar for the two groups . The drug cost/successfully treated patient for esmolol versus diltiazem w as $254 versus $437 at 6 hours and $529 versus $262 at 24 hours. Conclusions Although this is a small study, it suggests that esmolol is mor e effective in converting patients to normal sinus rhythm than diltiazem du ring the initial dosing period. No differences in conversion rates were obs erved between the two groups after 24 hours. Additional studies are needed to confirm whether esmolol is the initial drug of choice in patients with p ostoperative AF/AFL after coronary bypass surgery.