Effect on Circulation of Conversion of Atrial Fibrillation to Sinus Rhythm

Abstract
Treadmill exercise tests were performed in cardiac subjects before and after conversion from atrial fibrillation to sinus rhythm. The most striking changes following conversion were a marked reduction in exercise heart rate and increase in stroke volume and cardiac output. Exercise performance as judged by a standardized exercise test improved significantly in some but not all subjects following conversion. Duplicate control studies in nonconverting subjects failed in general to show these improvements. The results indicate that conversion from atrial fibrillation to sinus rhythm is worthwhile from a functional standpoint in patients with valvular heart disease, and is especially indicated after successful mitral commissurotomy.