cute myocardial infarctions (AMI) are usually caused by the rupture of coronary atheromatous plaque, which can evolve to a completely occlusive thrombus. 1 There have been a few reports of thrombus located close to the ostium of the coronary artery leading to myocardial infarction, 2-7 and we report an unusual case of AMI caused by a giant organized thrombus occupying the entire left sinus of Valsalva and intermittently obstructing the ostium of the left coronary artery (LCA).
Case ReportA 48-year-old Japanese man came to the emergency room by ambulance in December 1999 because of an initial episode of left anterior chest pain lasting 2 h. He had a history of smoking (30 cigarettes per day) and diabetes mellitus (hemoglobin A1c 7.1%), but he did not have a history of heart disease. He was not taking any medications.In the emergency room, the patient's pulse was regular at 100 beats/min, and his blood pressure was 124/91 mmHg. Auscultation of the heart and lungs indicated nothing abnormal. Chest X-ray examination showed mild enlargement of the heart, with a cardiothoracic ratio of 54%, but no apparent pulmonary congestion. Electrocardiography showed sinus rhythm, left axis deviation, and ST-segment depression in leads I, II, aVL and V3-6, indicative of an acute coronary syndrome (Fig 1).Emergency cardiac catheterization revealed neither organic stenosis nor thromboembolism in either coronary