Effect of single intraoperative dose of amiodarone in patients with rheumatic valvular heart disease and atrial fibrillation undergoing valve replacement surgery

Maintenance of sinus rhythm (SR) is superior to rate control in atrial fibrillation (AF). In order to achieve SR, we administered single-dose intravenous amiodarone intraoperatively and evaluated its effect on conversion of rheumatic AF to SR in patients undergoing valvular heart surgery. Patients were randomly assigned to amiodarone (n = 42) or control (n = 40) group in a double blind manner. The amiodarone group received amiodarone (3 mg/kg) intravenously prior to the institution of cardiopulmonary bypass and the control group received the same volume of normal saline. In the amiodarone group, the initial rhythm after the release of aortic cross clamp was noted to be AF in 14.3% (n = 6) and remained so in 9.5% (n = 4) of patients till the end of surgery. In the control group, the rhythm soon after the release of aortic cross clamp was AF in 37.5% (n = 15) (p = 0.035) and remained so in 32.5% (n = 13) of patients till the end of surgery (p = 0.01). At the end of first post-operative day 21.4% (n = 9) of patients in amiodarone group and 55% (n = 22) of patients in control group were in AF (p = 0.002). The requirement of cardioversion/defibrillation was 1.5 (+/-0.54) in amiodarone group and 2.26 (+/-0.73) in the control group (p = 0.014), and the energy needed was 22.5 (+/-8.86) joules in the amiodarone group and 40.53 (+/-16.5) in the control group (p = 0.008). A single intraoperative dose of intravenous amiodarone increased the conversion rate of AF to normal sinus rhythm, reduced the need and energy required for cardioversion/defibrillation and reduced the recurrence of AF within one day.