[Morphological spectrum of atrioventricular septal defects].

Morphology of atrioventricular septal defect was studied on 73 heart specimens. All of them had a defect of atrioventricular septum and adjoining parts of atrial and ventricular septum, a shortening of inflow parts of both ventricles, a malformation of atrioventricular valves and changed position of aortic valve. There was a great variability of all the studied structures and nearly continuous spectrum of specimens was found as for the ventricles' size, localization and diameter of the defect, communication between atria and ventricles, anatomy of the left ventricle outflow tract as well as the whole atrioventricular valvular apparatus and occurrence of associated heart malformations. A common ostium was formed in 52 cases (71.2%), two separated ostia were found in 21 cases (28.8%) but a continuous transition between both groups was noticed. Both groups showed a great variety of single cusps of atrioventricular valves (in shape, number and anchoring), of papillary muscles and of the size of atrioventricular communication. The finding of frequently associated heart malformations was important from the clinical point of view, especially of the obstructive malformations of the left ventricle. A great morphological variability needs individual surgical solutions, namely reconstruction of valves, closure of septal defects and correction of associated heart malformations.