Tetralogy of Fallot

Hearts with Fallot's tetrad from 33 children dying at the age from 14 days to 8 years were studied. Analysis of the morphological features of the defect revealed its typical anatomic signs: anteroleft shift of conic septum (oblique orientation); reorientation of the structures of inflow and outflow parts of the right ventricle infundibular pulmonary stenosis the occurrence of which may be due to all the structures and formations participating in the formation of the outflow part of the right ventricle. Four main types of stenoses were established. The most frequent cause of maximal stenosis of the blood flow through the right ventricle was demarcating muscle ring; a nonrestrictive defect of the ventricular septum (DVS). Three types of DVS in Fallot's tetrad were found: perimembranous, muscular, subarterial; dextroposition of the aorta, and right ventricular hypertrophy.