[Coronary artery embolism from ruptured plaque in the left main trunks with difficulty in detection of culprit lesion: a case report].

A 60-year-old man complained of severe chest pain and was emergently admitted to our hospital with a dignosis of anterior acute myocardial infarction. Emergent coronary angiography revealed significant stenosis in segment 7 and filling defect in segment 11 without flow delay. Haziness was observed in segment 5. Coronary thromboembolism was suspected, but the embolic source or culprit lesion was hard to detect. Intravascular ultrasonography detected ruptured plaque with lipid pooling in segment 5. Stent implantation for segment 5 was performed successfully and the patient had an excellent clinical course. Coronary thromboembolism is rare and intravascular ultrasonography may be useful to detect the culprit lesion.