Comparative efficacy and tolerance of esmolol to propranolol for control of supraventricular tachyarrhythmia

This multicenter, double-blind, randomized, parallel study compared the effectiveness and tolerance of intravenous esmolol with intravenous propranolol in patients with supraventricular tachyarrhythmia (heart rate [HR] greater than 120 beats/min). Efficacy was evaluated in 53 patients receiving esmolol and in 57 patients receiving propranolol. Patients randomized to esmolol received infusions of various doses of esmolol ranging from 50 to 300 micrograms/kg/min (each dose infused for 5 minutes) over a 30-minute titration period with intermittent placebo boluses of propranolol. Those randomized for propranolol received 1 mg/min for the first 3 minutes, and then another 3 mg from minutes 5 to 8 with continuous placebo esmolol infusion during the 30-minute titration period. A therapeutic response, defined by 20% or greater reduction in HR, HR less than 100 beats/min or conversion to normal sinus rhythm, was achieved in 72% of patients on esmolol compared with 69% of patients on propranolol (difference not significant). The therapeutic response was maintained in 67% of patients on esmolol and 58% of patients on propranolol (difference not significant) during a 4-hour maintenance period. Conversion to normal sinus rhythm occurred in 14% of esmolol patients and 16% of propranolol patients during titration and 10% of esmolol and 8% of propranolol patients during maintenance. After discontinuation of study drugs, a more rapid reversal of the reduction in HR was observed in esmolol patients compared with those patients receiving propranolol. Adverse reactions were seen in 29 (45%) patients on esmolol and 11 (18%) patients on propranolol. The principle adverse reaction was hypotension, which was predominantly asymptomatic and found in 23 patients receiving esmolol and 4 receiving propranolol.(ABSTRACT TRUNCATED AT 250 WORDS)