Hemodynamic effects after reversion from atrial fibrillation to sinus rhythm by precordial shock.

Abstract

DC [Direct current] precordial shock was applied to 27 patients with heart disease. Hemodynamic studies were obtained 24 hr. before and after shock. No anti-arrhythmic drugs were given. There were no significant changes in 6 control patients who failed to revert. Resting O2 consumptions were similar in 2 studies in all patients. Resting cardiac output increased 32% in 10 patients with mitral stenosis or insufficiency (p . 001), increased 37% in 4 patients with aortic valve disease (p . 005) but did not change in 6 patients with benign or lone fibrillation after reversion to sinus rhythm. The increased blood flow was due to greater stroke volume. During exercise following reversion cardiac output increased 27% in the mitral disease group but was unchanged in patients with lone fibrillation. The increment in heart rate during exercise significantly decreased after reversion in patients with mitral disease and benign fibrillation. We conclude that reversion from atrial fibrillation to sinus rhythm increases cardiac output significantly in patients with valvular heart disease, but not in those with benign fibrillation.