Intravascular ultrasound evaluation of ruptured plaque in the left main coronary artery misinterpreted as an aneurysm by angiography.

We report a patient who demonstrated a left main coronary aneurysm by angiography. Intravascular ultrasound (IVUS) revealed that it was in fact an ulceration, which indicated ruptured plaque. This case provides evidence that IVUS can permit a more powerful definition of ruptured plaque than angiography. On IVUS, ulceration exhibits significantly different characteristics from aneurysm.