Abstract
A 57-year-old man was admitted to an emergency department with chest pain which radiated to the left shoulder at rest. An electrocardiography showed sinus tachycardia with ST segment depression in the lateral leads. The blood tests did not reveal elevated serum cardiac enzymes, and echocardiography did not show regional asynergy. Coronary angiography showed no significant coronary stenosis but the left anterior descending artery exhibited severe compression during systole, which returned to normal during diastole. On iodine-123 beta-methyl-p-iodophenyl-pentadecanoic acid (123I-BMIPP) imaging, a decreased uptake of 123I-BMPP was observed in the anteroseptal segment. The etiology of ischemia in this case was considered to be myocardial bridging. He was treated with bisoprolol, and no ischemic changes were subsequently provoked on exercise electrocardiography tests. Myocardial bridging sometimes causes myocardial ischemia from the compression of the coronary artery at systole. In this case, tachycardia exacerbated myocardial ischemia due to myocardial bridging, which was confirmed by 123I-BMIPP imaging and exercise electrocardiography tests, and improved by the administration of beta adrenergic blockers.
