ST segment elevation myocardial infarction of a rare aetiology: an unexpected diagnosis.

A 43-year-old man presenting with acute coronary syndrome with ST segment elevation myocardial infarction underwent urgent coronary angiography. During the intervention, the patient was found to have several multiple filling defects with dynamic obstruction in the left coronary circulation. Thrombectomy was performed on distal left anterior descending artery and 2nd diagonal artery lesions with balloon angioplasty, which was unsuccessful. Considering the dynamic obstruction in the angiogram, immediate imaging was performed for structural evaluation of the heart. Cardiac CT revealed a circumferential groove on the heart, suggesting an external compression leading to dynamic obstruction of the coronary arteries on angiogram. Cardiac hernia, a very rare aetiology, was suspected to be the culprit for the ST segment elevation myocardial infarction. Thoracoscopy was performed, which revealed congenital cardiac hernia and a fibrous pericardial band encircling the apex. A left mini thoracotomy was performed to release the constriction imposed over the heart, with improvement in circulation.