Objective: To compare the efficacy and safety of intravenous (IV) amiodarone and procainamide for the treatment of atrial tachyarrhythmias (AT) in the critically ill.
Design: In this prospective study, patients were allocated to drug treatment on the basis of hospital identification number, even for procainamide and odd for amiodarone.
Setting: Patients were recruited from a teaching hospital ICU and did not include postoperative cardiac patients.
Patients and participants: 26 patients with AT sustained for at least 1 h and failure to respond to correction of possible precipitating factors were entered in the study. Exclusion criteria were systolic blood pressure (SBP) < 80 mmHg, and known hypersensitivity to either drug. Two patients with chronic atrial fibrillation (who received amiodarone) were later excluded from the analysis. In the final analysis, 14 patients received procainamide and 10 amiodarone.
Interventions: IV amiodarone (3 mg/kg followed by 10 mg/kg/24 h, with repeat dose of 3 mg/kg at 1 h if no response) or i.v. procainamide (10 mg/kg at 1 mg/kg/min followed by infusion of 2-4 mg/min for 24 h, with repeat dose of 5 mg/kg at 1 h if no response).
Measurements and results: In the procainamide group 10/14 (71%) and in the amiodarone group 7/10 (70%) had converted to sinus rhythm by 12 h. There was no significant difference in response between the groups. SBP was not significantly different from baseline after administration of either drug.
Conclusions: Procainamide and amiodarone appear to be safe and equally effective in the treatment of AT in the critically ill.