Management of cerebral embolism of cardiac origin.

The cardiac conditions most commonly associated with cerebral embolism are rheumatic heart disease (RHD), atherosclerotic heart disease (myocardial infarction and atrial arrhythmias) and other kinds of nonvalvular atrial fibillation (AF). The natural history of cerebral embolism from these cardiac sources is reviewed. Virtually all rheumatic hearts producing emboli have mitral stenosis, but not all of them are in AF. Of patients with RHD, 10--20% will experience a systemic embolus, and approximately half will have a recurrence, usually early. Of patients with a myocardial infarction, 5--12% will have a clinically apparent systemic embolus, and one-third to one-half have a recurrence, usually early. As many as 10--20% of patients with nonrheumatic AF have a systemic embolus. Anticoagulation reduces systemic embolism to 10--20% of the natural incidence in RHD, and it reduces embolic recurrences to 10--20% of the natural recurrence rate. Anticoagulation diminishes the incidence of emboli in myocardial infarction to 25% of the natural incidence. It is not known what effect anticoagulation has on the incidence of embolism in nonrheumatic AF. The data regarding the effect of valvulotomy and prosthetic valve placement in RHD are briefly reviewed. Recommendations are made for the use and timing of anticoagulation based on the available data.