ABSTRACT
Heart disease, especially atrial fibrillation (AF), is an established risk factor for ischemic stroke1,5,7,10-14. Mechanisms of cerebral embolism of cardiac origin have been discussed at length elsewhere12,13, as has the epidemiology of atrial fibrillation5,11,15-20. The prevalence of AF increases with age11. Among 244 blacks aged 65 and over in the Cardiovascular Health Study,
1.5% of men and 3.6% of women had ever been told by a doctor they had AF18. Among 4926 whites, rates were 6.0% in men and 4.8% in women. AF diagnosed by electrocardiogram (ECG) was reported in 1.1% of black men and 0.7% of black women compared to 4.0% and 2.7%, respectively, in whites (non-significant racial difference). The prevalence of abnormal left atrial size ranged from 13.9% in black women to 21.4% in white men. In one large US study, whites were more likely than blacks to have AF at ages over 50 years (prevalence in whites 2.2%, in blacks 1.5%, p < 0.001)19. Among patients with acute myocardial infarction (AMI) in a clinical trial, the frequency of atrial fibrillation prior to randomization was 1.8% in blacks and 6.7% in whites21.
