Single ventricle (morphologic study of 21 cases).

The morphological characters of 21 cases of single ventricle which constituted 1.63% of cases of congenital heart disease were studied. The single ventricular chamber with left ventricular characters was seen in 11 cases. In 8 of these, the great vessels were transposed with aorta arising from outlet chamber (SLL-7:SDD-1). Except in one case where there was common A-V valve, two A-V valve, two A-V valves entered the main chamber with some abnormality of A-V valves in all the cases. Bulbo-ventricular foramen was obstructive in 6 cases with resultant hypoplasia of aorta. Aortic arch anomalies were present in 5 of these. Valvular pulmonary stenosis was present in two. In 3 cases with normally related great vessels (SDS), bulbo-ventricular foramen was obstructive in two with hypoplastic pulmonary artery. Abnormalities of A-V valves were similar to the previous group. The incidence of single right ventricle was high in this series (47%). In half the cases, there was associated asplenia syndrome. This group in general showed common atrium with exception of one case, common A-V canal, both great vessels arising from same outflow with atrophic conal septum. Anomalies of pulmonary veins were common. The subsets observed were ADD-3, ADL-1, AL single trunk-1. In the remaining cases without asplenia, both A-V valves were present though some abnormalities were present in all. Systemic and pulmonary venous anomalies were rare. The subsets observed were SLL-3, SDL-1, SDD-1.(ABSTRACT TRUNCATED AT 250 WORDS)