Comparison of intravenous amiodarone versus intravenous amiodarone plus digoxin for rate control in intensive care patients with acute atrial fibrillation
Abstract:
Background : The optimal rate control approach for acute atrial fibrillation in intensive care unit patients has not been established. Either amiodarone or digoxin is widely used to decrease the ventricular rates but combination of both has not been proved its efficacy. Objective : This study was designed to determine the efficacy of intravenous combination of amiodarone and digoxin vs intravenous amiodarone alone for acute ventricular rate control in intensive patients with acute atrial fibrillation. Design : Prospective, randomized open label study. Methods : Forty-two patients with atrial fibrillation and uncontrolled ventricular rates were randomized to receive either an intravenous combination of amiodarone (5 mg/kg intravenously in 30 minutes ,then 1 mg/min for 6 hours, followed by 0.5 mg/min over next 18 hours) and digoxin (0.25 mg intravenously every 2 hours, total 0.75 mg) ,or an intravenous amiodarone alone(identical amount) and were continuously monitored EKG and drug adverse effects. Result : At 8 hours, the mean heart rates in both groups decreased clinically significant : in amiodarone group from 134 +/- 21.7 beats/min to 95.4 +/- 26.6 beats/min(p<0.001), in combination group from 140 +/- 16.2 beats/min to 91.5 +/- 25.4 beats/min (p<0.001). Comparing between two groups, treatment with combination drugs demonstrated slightly better ventricular rate control at 8 hours (91.5 +/- 25.4 beats/min in combination group vs 95.4 +/- 26.6 beats/min in amiodarone alone group, p = 0.64). By the end of 24 hours treatment period : 14 patients (67.7%) in combination group and 15 patients (71.6%) in amiodarone alone group had returned to sinus rhythm (p = 1.0). Adverse effects occurred 49% in combination group (5 hypotension, 1 phebitis, 4 bradyarrhythmia) where as 29% in amiodarone alone group (5 hypotension, 1 phebitis).There was no life threatening adverse effect, interestingly we found bradyarrhythmia in combination group only, including one patient who developed complete AV block. Conclusions : Combination therapy, as compared with amiodarone alone, was not significantly improved efficacy for acute ventricular rate control but increased bradyarrhythmic adverse effect