Objective: To analyze the efficacy of an IV combination of diltiazem and digoxin vs IV diltiazem alone for acute ventricular rate control in patients with atrial fibrillation.
Design: Prospective, randomized, open-label study.
Patients and methods: Fifty-two patients with atrial fibrillation and uncontrolled ventricular rates were randomized to receive either an IV combination of diltiazem and digoxin or IV diltiazem alone and were observed for 12 h. The successful rate control was defined as a ventricular rate < 100 beats per minute (bpm) persisting for 1 h or conversion to sinus rhythm. The loss of rate control was defined as an increase in the ventricular rate to > 100 bpm persistently for > 30 min or rebound to atrial fibrillation.
Results: In both treatment arms (n = 26 each), all patients achieved successful and comparable ventricular rate control at 12 h. The mean (+/- SD) time taken to achieve successful rate control was shorter in the combination arm (15 +/- 16 vs. 22 +/- 22 min). Six patients in the combination arm and 11 in the diltiazem-alone arm experienced episodes of loss of rate control. This loss in the combination arm was less than that in the diltiazem-alone arm (14 vs 39 episodes; p = 0.05). The loss of rate control per patient in the combination arm was also less than that in the diltiazem-alone arm (2.0 +/- 1.0 vs. 3.5 +/- 1.9 episodes per patient; p = 0.04).
Conclusions: This study demonstrates that in patients with atrial fibrillation who have a rapid ventricular response, the IV combination of diltiazem and digoxin results in a more efficacious ventricular rate control with fewer fluctuations than that achieved by therapy with IV diltiazem alone.