[Alterations of auriculoventricular valves in single ventricles and similar abnormalities]

The morphologic changes of the atrio-ventricular valve in 30 cases of lone ventricle or similar anomalies have been: 1. Common atrio-ventricular valve (8 cases); 2. Abnormally small left atrio-ventricular valve (15 cases) 3. Parachute-like left atrio-ventricular valve (5 cases); 4. Atresia of one of the atrio-ventricular valves (2 cases); 5. Atrio-ventricular valves corresponding to a tricuspid valve which were bicuspid (6 cases); 6. Accessory valvular orifices (5 cases); 7. Valvular clefts (3 cases); 8. Insufficient valvular tissue (4 cases); 9. Accessory valvular tissue (7 cases); 10. Anomalies of orientation of the anterior in relation with the posterior mitral valve leaflet (7 cases); 11. Peculiar orientation of the valve in relation with the outflow tract, resulting in a "functional overlap" (1 case); 12. Muscle column on the posterior wall of the main ventricular chamber (18 cases); 13. Papillary muscle distribution alterations (29 cases). The embryologic, diagnostic and surgical signification of all these anomalies were considered.