Association of left dominant coronary arterial system with congenital bicuspid aortic valve.

Clinical angiographic studies have documented an association of left dominance of the coronary arteries with aortic stenosis and congenital bicuspid aortic valve. The postmortem arteriograms of 973 autopsy patients were reviewed for pattern of coronary dominance and the hearts examined for the nature of any aortic valve disease. There were 673 hearts (70 percent) with a right dominant pattern, 198 (20 percent) with equal dominance and 102 (10 percent) with left dominance. Of 34 hearts with congenital bicuspid aortic valve, 10 (29 percent) had left dominance, a difference significant at the 0.005 level. Of 44 hearts with calcific aortic stenosis, an acquired valve lesion, 9 (20 percent) had left dominance. Rheumatic aortic valve disease (47 cases) and aortic regurgitation (27 cases) had no apparent relation to the coronary arterial pattern. The results confirm the association of left coronary arterial dominance with congenital bicuspid aortic valve. It is suggested that a left dominant coronary system may arise as a consequence of disproportionately decreased blood flow in the left heart chambers, one cause of which is aortic valve stenosis, during early cardiogenesis.