Atrial size, atrial fibrillation, and stroke.

M-mode and two-dimensional echocardiographic images were reviewed retrospectively in 20 patients with atrial fibrillation and ischemic stroke with no known valvular disease and in 20 patients with atrial fibrillation without known stroke. Left atrial size was measured and analyzed without knowledge of patient grouping. Two-dimensional echocardiography showed that 90% of the stroke patients had left atrial enlargement compared with only 20% in the nonstroke group. This finding suggests that left atrial enlargement may convey additional stroke risk in patients with atrial fibrillation.