Assessment of silent microembolism by magnetic resonance imaging after cardioversion in atrial fibrillation.

Introduction And Objectives: To study electrical cardioversion in patients with atrial fibrillation as a potential cause of acute ischemic brain lesions.

Methods: We performed prospective analysis of 62 consecutive patients (62 [10] years, 16 female). All of them were anticoagulated for at least 3 weeks with an international normalized ratio of 2.69 (0.66). In all cases a magnetic resonance imaging of the brain was performed before and 24h after the cardioversion, including diffusion-weighted sequences. A neurological exploration was also performed before and after the procedure, using the modified Ictus on the National Institute of Health Stroke Scale and the modified Rankin scale. Written informed consent was obtained in all cases.

Results: Of the 62 patients, 51 (85%) reverted to sinus rhythm. The neurological examination showed no changes after cardioversion. The pre-procedure magnetic resonance imaging showed microvascular disease in 35 (56%), including 2 patients with known cerebrovascular disease, and did not depict new clinically silent ischemic areas after cardioversion.

Conclusions: After electrical cardioversion no acute ischemic lesions in the brain nor alteration in the neurological scales were found. Nevertheless, in 35 patients (56%) with persistent atrial fibrillation, the magnetic resonance imaging showed clinically silent ischemic lesions.