T HE INFREQUENT REPORTS of mitral insufficiency on a congenital basis rcflect the apparent rarity of this condition. Aneurysmal dilatation of the left atrium in a 5year-old girl with clinical findings suggesting mitral insufficiency has been described by Semans and Taussig in 1938.1 Postmortem examination of this patient revealed thickening of the mitral and tricuspid valves, saccular dilatatio...
