To establish the value of adjuvant dl-sotalol to digoxin for control of the ventricular response in chronic atrial fibrillation, 60 patients were evaluated in a multicenter, randomized, double-blind, parallel, placebo-controlled study. Patients were evaluated with serial ambulatory ECG monitoring and exercise testing during stable digoxin dosing and then with the addition of either a placebo or dl-sotalol, 80 mg/day, or dl-sotalol, 160 mg/day. The combination of digoxin and dl-sotalol, at either 80 or 160 mg/day, resulted in a statistically significant reduction in heart rate at rest and with exercise during both exercise testing and ambulatory monitoring. No significant difference was observed between the two doses of dl-sotalol. There was no significant difference with regard to symptoms or side effects among the three groups. In summary, dl-sotalol was noted to be a safe and effective adjuvant to digoxin for control of the ventricular response in chronic atrial fibrillation.
