SEVERE CONGENITAL STENOSIS OF THE LEFT CORONARY-ARTERY OSTIUM AND ITSPOSSIBLE PATHOGENESIS ACCORDING TO CURRENT KNOWLEDGE ON CORONARY-ARTERY DEVELOPMENT

We report a 72-year-old woman with severe congenital stenosis of the l eft coronary artery orifice and clinically significant atherosclerotic changes in both the right and left coronary arteries. The stenotic os tium was located at the point at which the left and posterior aortic v alve leaflets joined to form the left commissure, just at the distal v ertex of the left interleaflet triangle, between the left and posterio r aortic sinuses. The right coronary artery was more developed in size than usual, whereas the left coronary artery consisted of a short lef t main coronary trunk that bifurcated into left anterior descending an d left circumflex arteries. The left coronary artery system was filled retrogradely through two vessels proceeding from the right coronary a rtery, namely, the conal artery and a well-developed branch that ran a cross the interventricular septum. This abnormal arrangement of the co ronary arteries showed striking functional similarities with atresia o f the left main coronary artery. Current knowledge on the morphogenesi s of the coronary arteries suggests that the present anomalous coronar y artery pattern resulted from the penetration of the anticipated left coronary artery system into the aorta at a totally erroneus site. Thi s hindered the normal development of the ostium, which subsisted as a punctiform, practically nonfunctional opening. (C) 1998 by Elsevier Sc ience Inc.