Severe isolated left mainstem coronary artery stenosis. A case report.

A 33-year-old white man had exertional angina pectoris, followed by angina pectoris at rest, and then episodes of ischaemic acute pulmonary oedema associated with angina pectoris. Selective coronary angiography delineated an isolated long-segment stenosis of the left mainstem coronary artery with no other lesions. We believe that the mainstem obstruction was due to coronary artery fibromuscular hyperplasia, a condition rarely affecting the coronary artery circulation. At operation three coronary artery bypass grafts were inserted, one to the left anterior descending artery and two to the left circumflex coronary artery, with a most successful result. The patient's recurrent acute pulmonary oedema was due to severe myocardial ischaemia; the possibility of superadded coronary vasospasm aggravating the obstruction cannot be entirely discounted.