Abstract

In a necropsy study, the conjoined cusps of 50 congenitally and 50 acquired bicuspid aortic valves most commonly involved the right and left aortic cusps. In hearts with congenitally bicuspid aortic valves, the left coronary ostium arose at or above the aortic sinotubular junction in 44 per cent, whereas the incidence for the left coronary ostium in the acquired group was 20 per cent and that for the right coronary ostium in both groups was less than 20 per cent. In hearts with congenitally bicuspid aortic valves, the incidence of left coronary dominance (26%) was higher than in normal hearts. In hearts with apparently acquired bicuspid aortic valves, this incidence was also higher than normal, possibly because of acquired fusion of atypical congenitally bicuspid valves in some cases. In both types of aortic valve disease, the length of the left main coronary artery was similar; this length, however, was significantly shorter in hearts with left coronary dominance than in those with right or shared dominance.