Myocardial infarction associated with thyrotoxicosis.

Myocardial infarction occurs rarely with thyrotoxicosis. A 34-year-old woman with thyrotoxicosis sustained a transmural myocardial infarction and subsequently on cardiac catheterization studies had no significant coronary arterial disease but only residual apical wall akinesia. Thyroid hormone may directly influence myocardial oxygen supply and demand and, by some unknown mechanism exclusive of major coronary arterial blood supply, cause a critical imbalance resulting in angina pectoris and myocardial infarction.