High risk of systemic embolism in hypertrophic cardiomyopathy.

Six of 66 patients with hypertrophic cardiomyopathy had an embolic event during an average observation period of 3.73 years. Five of these had probable cerebral embolism, while 1 patient had a femoral artery embolism. The calculated incidence of systemic embolism was 2.4% per patient year. All embolic events occurred in the patients with atrial fibrillation. In comparison to patients without systemic embolism with or without atrial fibrillation, the cardiothoracic ratio was greater, the cardiac index was lower and the left atrial dimension tended to be greater in those patients with systemic embolism.