Myocardial Infarction in Thyrotoxicosis

Myocardial Infarction occurs rarely in thyrotoxicosis. About 13 cases have been reported in the literature; three additional cases are described. The features in these 16 cases are reviewed. There are more males (nine) than females (seven), and the mean age is 55·9 years. Infarction occurs often within one year of the onset of thyrotoxicosis. A history of typical chest pain is often absent. The absence of hypertension, hypercholesterolæmia and obesity suggests that coronary thrombosis is unlikely to be the chief cause of myocardial Infarct in thyrotoxicosis. Also the frequent absence of atrial fibrillation suggests that the embolic theory of myocardial infarction in thyrotoxicosis is not important. Direct damage of the coronary arteries and myocardium in thyrotoxicosis leading to subsequent infarction cannot be excluded.