Extrinsic compression of the left main coronary artery is a rare cause of c
oronary ischemia, We describe a 35-year-old Asian woman with complete asymp
tomatic occlusion of the left main coronary artery by a large aortic pseudo
aneurysm. She underwent repair of the pseudoaneurysm and coronary artery by
pass grafting at the Mayo Clinic in Rochester, Minn, The differential diagn
osis is discussed. Based on this patient's age and associated vascular lesi
ons, we conclude that Takayasu arteritis was the most likely cause of her c
ondition.