Silent culprit: Left atrial myxoma presenting as anterior STEMI

Primary cardiac tumors are extremely rare, with myxomas being the most common. While systemic embolization is a known complication of myxomas, coronary embolism is exceedingly rare. We report a case of a 70-year-old woman with anterior STEMI and no clear culprit lesion who was later found to have a large left atrial myxoma with mobile thrombus. This 70-year-old woman with hypertension, diabetes, and tobacco use presented with acute retrosternal chest pain. Initial ECG showed ST-segment elevation and Q waves in leads V2-V6. Coronary angiogram showed obstructive coronary arteries: 70% proximal LAD, 80% proximal-to-mid RCA, 43% distal LM. No clear culprit lesion to explain STEMI found by both angiography and intravascular imaging. A percutaneous coronary intervention was performed on the LAD and RCA with resolution of chest pain and improved, but persistent, ST elevation on ECG. On the next day, she developed recurrent chest pain; her ECG showed slightly increased ST elevation. Echocardiogram revealed EF 35% and a large myxoma with mobile thrombus attached. In this case, patient’s STEMI was suspected to be embolic in origin. Despite atherosclerotic risk factors and diffuse CAD on angiogram, no clear culprit lesion explained the persistent transmural ischemia seen on ECG, raising the possibility of heavy microvascular embolization. Keywords: Myxoma; acute coronary syndrome; myocardial infarction