This study examined the effectiveness of intravenous amiodarone for rapid control and prevention of recurrent life-threatening ventricular tachyarrhythmias associated with cardiovascular collapse. In 22 critically ill patients with coronary artery disease (mean ejection fraction 27 +/- 13%), recurrent ventricular tachyarrhythmias proved refractory to 3.7 +/- 1.1 (mean +/- standard deviation) conventional antiarrhythmic drugs. In the 24-hour period before intravenous amiodarone treatment, patients experienced 2.4 +/- 2.3 (range 1 to 9) episodes of life-threatening ventricular tachycardia, ventricular fibrillation or both, requiring 4.0 +/- 3.9 direct current cardioversions. Within the 24 hours after initiation of intravenous amiodarone therapy (900 to 1,600 mg/day), 20 of 22 patients remained alive and had 1.1 +/- 1.6 episodes of life-threatening ventricular arrhythmias, requiring 1.9 +/- 3.1 direct current cardioversions. In the second 24-hour period, there were 19 survivors and life-threatening arrhythmias were reduced to 0.4 +/- 0.7 episode/patient requiring 0.4 +/- 0.9 direct current cardioversion. Overall, arrhythmias were controlled in 11 of 22 (50%) patients within the first 24 hours, and in 14 of 22 (64%) in the second 24 hours. Intravenous amiodarone therapy was well tolerated. Twelve patients were discharged from the hospital and 8 remained alive at a mean follow-up of 22 +/- 14 months. Thus, in critically ill patients, intravenous amiodarone may be useful for rapid control of spontaneous, refractory, life-threatening ventricular tachyarrhythmias.