Acute anterior myocardial infarction (MI) due to left main coronary artery thrombosis is a rare entity with a very high mortality rate. A 72-year-old male patient was admitted with chest pain of two-hour onset that appeared during syncope. Electrocardiography showed first-degree AV block, right bundle branch block, left anterior fascicular block, ST-segment elevation of 5 mm in lead aVR, and significant ST depression in anterior derivations, suggesting acute anterior MI. Coronary angiography showed total occlusion of the left main coronary artery. During consultation for emergency operation, he developed hypotension. An intra-aortic balloon pump was inserted and inotropic support was initiated. He required several attempts of cardioversion due to persistent attacks of ventricular tachycardia. He developed respiratory arrest, requiring endotracheal intubation mechanical ventilation. The patient died due to recurrent attacks of ventricular fibrillation and subsequent development of asystole during primary percutaneous coronary intervention.