Atrial Fibrillation — Risk Marker for Stroke

Atrial fibrillation not related to valvular heart disease (nonvalvular atrial fibrillation) is associated with nearly half the arterial emboli presumed to be of cardiac origin. It starts at a mean age of 64 years, affects 2 to 5 percent of the general population over the age of 60 (more than 1 million people), and is associated with a fivefold increase in the risk of ischemic stroke and a 5 to 7 percent yearly risk that increases with age. Cerebral infarction eventually occurs in up to 35 percent of patients with nonvalvular atrial fibrillation. The risk is even higher if “silent”…