C63. Myocardial bridging on coronary angiography: an innocent bystander or a culprit in myocardial infarction?

Abstract Myocardial bridging is one of the nonatherosclerotic causes of coronary artery disease and is characterized by muscles overlying the intramyocardial course of a major epicardial coronary artery segment, leading to systolic compression. This condition is usually benign but can be associated with unstable angina, myocardial infarction, and death. We report herein a myocardial infarction associated with a subtotal systolic narrowing of the LAD by a myocardial bridge. A 57-year-old-man with chronic heart failure caused by myocardial bridging post-non-ST elevation myocardial infarction and hypertensive heart disease. The electrocardiography showed sinus rhythm, echocardiography shows normal left and right ventricular function, regional wall motion abnormality, grade I diastolic dysfunction and “milking effect” was observed in the mid-segment of the left anterior descending coronary artery on the coronary angiogram. Schwarz type C is categorized in this case, β-blockers and calcium channel blockers remain the mainstay of treatment and relieve hemodynamic disorders caused by myocardial bridging by decreasing heart rate, increasing the period of diastolic coronary filling, and decreasing coronary artery contractility and compression. Other diagnostic modalities needed if symptoms persist despite optimal medical therapy and myotomy, coronary artery bypass graft, or stent implantation can be considered in these patients. At the six-month follow-up visit, the patient had no acute coronary syndrome event, but chest pain and heart failure were felt occasionally.