Objectives: This study investigated the hemodynamic effects of oral sotalol during both sinus rhythm and paroxysmal atrial fibrillation.
Background: The hemodynamic effects of most antiarrhythmic drugs have been characterized in subjects during sinus rhythm. However, there are no data concerning these effects on the paroxysmal tachyarrhythmias.
Methods: In 17 patients with paroxysmal atrial fibrillation and without heart failure (aged 62 +/- 11 years, ejection fraction 51 +/- 4%), an electrophysiologic-hemodynamic study was performed twice. In the first study, hemodynamic variables were evaluated both during sinus rhythm and after the induction of atrial fibrillation. Sotalol (160 or 240 mg/day) was administered for 6 to 7 days and the study was then repeated with the same methods.
Results: The drug significantly diminished heart rate during both sinus rhythm and atrial fibrillation. During sinus rhythm, sotalol did not change systemic pressures and significantly increased left and right ventricular end-diastolic, left and right atrial and pulmonary pressures. Cardiac index decreased, whereas stroke volume was unchanged after the drug. Ejection fraction and left ventricular end-diastolic and end-systolic volumes evaluated by echocardiography were unchanged after sotalol. During atrial fibrillation, the drug had less evident effects on cardiac function. Left ventricular end-diastolic, left atrial and pulmonary pressures did not increase significantly.
Conclusions: The hemodynamic changes induced by oral sotalol appear to be mainly related to an involvement of ventricular distensibility; this effect is less evident during atrial fibrillation than during sinus rhythm. In patients with paroxysmal atrial fibrillation without heart failure treated with oral sotalol, a recurrence of the tachyarrhythmia is hemodynamically well tolerated.