Hemodynamic effects of oral sotalol during both sinus rhythm and atrial fibrillation.

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.