INTRAVENOUS SOTALOL FOR THE TERMINATION OF SUPRAVENTRICULAR TACHYCARDIA AND ATRIAL-FIBRILLATION AND FLUTTER - A MULTICENTER, RANDOMIZED, DOUBLE-BLIND, PLACEBO-CONTROLLED STUDY

Sotalol is an antiarrhythmic agent with combined beta-blocking and class III antiarrhythmic properties. This study was designed to assess the safety and efficacy of sotalol in terminating supraventricular tachycardia (SVT), atrial fibrillation (AFib), and atrial flutter (AFI). Ninety-three patients with spontaneous or induced SVT (n = 45) or AF (AFib or AFI; n = 48) with a ventricular rate of greater than or equal to 120 beats/min were studied. In the first phase, the double-blind phase, patients were randomly assigned to receive placebo or intravenous (iv) sotalol, 1.0 or 1.5 mg/kg. If SVT or AF did not convert to sinus rhythm or if the ventricular rate did not slow to < 100 beats/min within 30 minutes, patients then entered the second phase, the open-label phase, which also lasted 30 minutes, and were given 1.5 mg/kg iv sotalol. In the SVT group, during the double-blind phase conversion to sinus rhythm occurred in 2 (14%) of 14 of patients who received placebo, 10 (67%) of 15 who received sotalol, 1.0 mg/kg (p < 0.05 vs placebo), and 10 (67%) of 15 who received 1.5 mg/kg sotalol (p < 0.05 vs placebo); during the open-label phase, 1.5 mg/kg iv sotalol converted 7 (41%) of 17 of patients. In the AF group, during the double-blind phase conversion to sinus rhythm occurred in 2 (14%) of 14 of patients who received placebo, 2 (11%) of 18 who received 1.0 mg/kg sotalol (p not significant [NS] vs placebo), and 2 (13%) of 16 who received 1.5 mg/kg sotalol (p = NS vs placebo); in these groups, a >20% reduction of ventricular rate without conversion to sinus rhythm occurred in 0 (0%) of 14, 13 (72%) of 18 (p < 0.05 vs placebo), and 12 (75%) of 16 of patients (p < 0.05 vs placebo), respectively; during the open-label phase, 1.5 mg/kg iv sotalol converted 7 (30%) of 23 of patients. The most common adverse events were hypotension and dyspnea. During the double-blind phase they occurred in 10% of patients who received placebo, 9% of those who received 1.0 mg/kg iv sotalol (p = NS vs placebo), and 10% of those who received 1.5 mg/kg iv sotalol (p = NS vs placebo). Most of these events were mild to moderate, but all were transient and clinically manageable. In conclusion, iv sotalol is safe and effective for acute termination of SVT and for acute slowing of ventricular rate during AF but not for termination of AF at doses to 1.5 mg/kg.