Intravenous amiodarone in the treatment of refractory life-threatening cardiac arrhythmias in the critically ill patient.

Eleven critically ill patients with life-threatening cardiac arrhythmias refractory to currently approved antiarrhythmic drugs were treated with intravenous amiodarone. Two patients had acute myocarditis, five had acute myocardial infarction, two had left ventricular failure secondary to ischemic heart disease, one had Wolff-Parkinson-White syndrome, and one manifested postoperative atrial fibrillation. Eight of the patients had severe cardiac failure and five had hypotension requiring intravenous dopamine. Five patients were treated for recurrent ventricular fibrillation, two for recurrent ventricular tachycardia, and four for recurrent atrial arrhythmias. Six patients had repeated cardioversions. The arrhythmias had lasted a mean of 88.3 hours resistant to a mean of 2.7 different intravenous antiarrhythmic drugs. The ventricular arrhythmias did not recur after commencing intravenous amiodarone, but some minor atrial arrhythmias occurred for 24 hours. One patient died of intractable left ventricular failure, chronic obstructive lung disease, and respiratory arrest during treatment. The dose of amiodarone was 150 mg over 5 minutes, followed by 600 mg/24 hr for 3 to 4 days; one patient on total parenteral nutrition required intravenous amiodarone for 20 days. Hypotension, cardiac failure, and bradyarrhythmias were not induced by this treatment. Intravenous amiodarone can be used safely in critically ill patients with impaired left ventricular function to control life-threatening refractory cardiac arrhythmias.