PROMINENT VENOUS VALVES IN HYPOPLASTIC RIGHT HEARTS

To investigate the hypothesis that embryologic abnormalities in the ve nous valves may be associated with abnormal cardiac development, we ex amined the right atrial morphologic characteristics in 20 hearts with underdevelopment of the right heart and 17 normal hearts. In the study group, 16 (80%) of the patients had significantly enlarged eustachian valves, one (5%) was slightly enlarged, and three (15%) were smaller than expected. Five (25%) had cor triatriatum dexter. In comparison, e ustachian wives in the control specimens were prominent in only one (6 %), normal in five (29%), and almost absent in eight (47%). The thebes ian valve was also more prominent in the study cohort when compared wi th controls (p < 0.05). No other morphologic features of the right atr ium analyzed in this study differed from those found in normal specime ns. We speculate that failure of the venous valves to regress appropri ately may create abnormalities in fetal circulation that predispose th e fetus to maldevelopment of the right heart structures.