Obstructive Giant Left Atrial Myxoma Concurrent with Very High-Risk Acute Coronary Syndrome Presenting as Cardiogenic Shock: A Rare Dual Pathology

Background: Primary cardiac tumors are exceptionally rare, with cardiac myxomas being the most common benign type, typically originating in the left atrium. Despite their benign histopathological nature, these tumors can lead to serious complications, including intracardiac obstruction, embolic events, and even sudden cardiac death. The coexistence of a Left Atrial (LA) myxoma and Coronary Artery Disease (CAD) is an unusual clinical finding. This report highlights the importance of recognizing cardiac myxoma as a potential contributor to high-risk acute coronary syndrome and hemodynamic instability. Case Illustration: A 57-year-old man presented with recurrent chest pain and shortness of breath, consistent with very high-risk Non–ST Elevation Myocardial Infarction (NSTEMI) and cardiogenic shock. Transthoracic Echocardiography (TTE) revealed a large LA mass causing functional mitral valve obstruction, highly suggestive of a myxoma. Further evaluation with transesophageal echocardiography confirmed a giant, highly mobile mass intermittently occluding the mitral inflow. Coronary angiography revealed significant Two-Vessel Coronary Artery Disease (CAD2VD), including chronic total occlusion of the Left Circumflex Artery (LCx). The patient subsequently underwent urgent combined surgical excision of the tumor and Coronary Artery Bypass Grafting (CABG). Histopathological examination confirmed the diagnosis of cardiac myxoma. The postoperative course was uneventful, with marked clinical improvement, complete resolution of symptoms, and preserved ventricular function on follow-up echocardiography. Conclusions: This case of very high-risk NSTEMI with cardiogenic shock was further complicated by a large LA myxoma causing dynamic mitral obstruction and diastolic inflow collapse. Early recognition using multimodal imaging and prompt surgical management are essential to prevent catastrophic hemodynamic deterioration and improve patient outcomes.