Anomalous Attachment of Mitral Valve Causing Subaortic Atresia

In a newborn female infant with persistent common atrioventricular canal, subaortic atresia resulting from attachment of the anterior mitral leaflet to the ventricular septum was observed. The cavity of the left ventricle was hypoplastic, while the wall was hypertrophied. The case illustrates the most severe degree of subaortic obstruction that may result from anomalous attachment of the mitral valve to the ventricular septum. Also present were multiple spleens, and other cardiovascular anomalies. The last included junction of a persistent left superior vena cava with the left atrium, absence of the coronary sinus, absence of the limbi of the fossa ovalis, and an anomalous connection of the right pulmonary veins to the right atrium.