Cerebral blood flow before and after cardioversion of atrial fibrillation.

In nine patients with atrial fibrillation (AF) of less than 3 months' duration, CBF was measured the day before and after and again 30 days after electrical cardioversion therapy to sinus rhythm. The day before cardioversion therapy, median CBF (expressed as initial slope index 1, ml/100 g.min-1) was 35.8 and the day after it was 37.1. After 30 days in sinus rhythm, CBF was 39.4 (NS), although the end-tidal PCO2 values were lower than the pretreatment values. After correction for changes in end-tidal PCO2, the median CBF had increased significantly from 35.8 to 40.3 on day 1 and to 46.7 on day 30. The reduced CBF during AF could be a contributing factor in the development of cerebrovascular complications in patients with AF.