Hemodynamic performances in patients treated with sotalol after electrical cardioversion of atrial fibrillation.

The negative inotropic effect of nearly all antiarrhythmic drugs, especially important in patients with impaired left ventricular function, represents a major drawback of medical therapy. The aim of this study is to evaluate the atrial and ventricular function and the exercise capacity in patients with mild heart failure treated with d,l-sotalol after electrical conversion of atrial fibrillation. The study included patients with persistent atrial fibrillation (for more than 2 weeks but less than 1 year) and mild heart failure (< or = class II NYHA). All patients had comparable basal echocardiographic findings, and received captopril. After successful cardioversion the patients were randomized in two groups: group 1 treated with sotalol (mean dose 240 mg q.d., max. 320 mg) and group 2--without sotalol. The drop-out criterion was the failure to maintain sinus rhythm. Finally, in the study remained 17 patients (10 men, 7 women, aged 41-60 years); group 1 included 10 patients and group 2-7 patients. They were assessed by quantitative echocardiography + Doppler and by standard ecg exercise test at less than 1 month but more than 2 weeks, and at 1, 3, and 6 months. When first evaluated (2 weeks-1 month), peak A wave velocity and atrial filling ratio were higher in group 2 than in group 1 (37 +/- 10 cm/s vs 20 +/- 5 cm/s and 23% +/- 7 vs 13% +/- 5, respectively) and group 1 had also a lower exercise tolerance (80 +/- 25 W vs 110 +/- 10 W). There were no significant differences between groups 1 and 2 in left atrial and left ventricular dimensions, ejection fraction and E wave deceleration time. After 1 month there were no significant differences in Doppler characteristics, echocardiographic parameters and exercise tolerance between the two groups. Group 1 remained at a lower heart rate and had a lower maximal double product (17250 mmHg/min vs 22100 mmHg/min) corresponding to a lower cardiac work. At 3 and 6 months there were no significant changes in all characteristics between the two groups. In conclusion, sotalol seems to be a well tolerated antiarrhythmic agent in patients with mild heart failure, after conversion of persistent atrial fibrillation. In this setting: 1. Sotalol could reversibly amplify the effect of atrial stunning after electrical cardioversion of atrial fibrillation, but this effect is brief. 2. Sotalol has no relevant negative inotropic effect, at least not in association with captopril. 3. Sotalol improves the effort capacity.