A Case of Acute Myocardial Infarction Associated with Hyperthyroidism

Hyperthyroidism is related with cardiac complications, such as heart failure, atrial fibrillation, heart block and coronary artery spasm. A myocardial infarction associated with hyperthyroidism has never been reported. A 28-year-old man presented with chest pain at the emergency room. He had had four year history of thyrotoxicosis. On physical examination, exophthalmos and a 11x5 cm sized goiter were found on the anterior of the neck. His electrocardiogram showed sinus tarchycardia ST elevation, with Q waves in leads V1 to V3. The creatine kinase-MB level was 42 U/l, cardiac troponin T 0.61 mg/dL and troponin I 2.36 mg/dL. Elevated levels of thyroid hormones, 193 ng/mL T3, 13.6 ng/mL T4 and 2.17 ng/dL free T4 were demonstrated, with a suppressed TSH level of 0.02 miicroliterU/mL and positive anti-microsomal antibody. A two dimensional echocardiography showed septal akinesia, and a diagnostic coronary angiogram total occlusion of the middle left anterior descending artery (LAD). With the aid of ReoPro(r) infusion, the LAD and the first diagonal branch were successfully recanalized using kissing balloon angioplasty. He had an uneventful recovery and no restenosis was demonstrated on the 6-month follow-up coronary angiogram.