One thousand autopsied cases were studied to determine the incidence of embolism from the atria in arteriosclerotic heart disease. In this study, it was found that 1 case of embolization occurred in a total of 52 patients with atrial fibrillation (2%), and 2 cases of embolization occurred in a total of 243 cases who were nonfibrillators (0.8%). Atrial embolization was uncommon in arteriosclerotic heart disease regardless of the prevailing atrial rhythm during life. This situation is contrasted with that present in rheumatic heart disease where atrial fibrillation is associated with a definitely increased risk of embolization.
Beer DT, Ghitman B. Embolization from the Atria in Arteriosclerotic Heart Disease. JAMA. 1961;177(5):287-291. doi:10.1001/jama.1961.03040310005002