Amiodarone versus diltiazem for rate control in critically ill patients with atrial tachyarrhythmias

60 critically ill patients with recent-onset atrial tachyarrhythmias (atrial fibrillation n=57, atrial flutter n=2, atrial tachycardia n=1) and a heart rate consistently >120 beats/min over 30 mins, mean age 67 +/- 10 years, APACHE III score 70 +/- 30.

Amiodarone administered as either a 300-mg IV bolus (Group 2) or a 300-mg IV bolus followed by 45 mg/hr continuous infusion for 24 hrs (Group 3).

Diltiazem administered as a 25-mg IV bolus followed by a continuous infusion of 20 mg/hr for 24 hrs (Group 1).

>30% rate reduction within 4 hrssurrogate