Conal anatomy in aortic atresia, ventricular septal defect, and normally developed left ventricle

Summary Although aortic valve atresia is usually associated with severe underdevelopment of the mitral apparatus and left ventricle, in rare cases of aortic atresia, the left ventricle may be of normal size, or even enlarged. This occurrence seems related to the presence of a significant ventricular septal defect. We have presented the morphologic findings in seven patients with aortic atresia and normally developed left ventricle, (six necropsied patients, and one studied angiocardiographically). Four autopsied patients had conal type ventricular septal defects, characterized in three by conoventricular malalignment. Subaortic atresia in these patients resulted from leftward deviation of the conal septum. One patient with aortic atresia and well-developed left ventricle had a membraneous defect, and one patient had a complete A-V canal. The ventricular septal defect in the patients with conoventricular malalignment are very similar to the conal VSD observed in patients with aortic arch interruptions. Although ultimate survival with these uncommon groupings of anomalies necessitates patency of the ductus arteriosus, clinical recognition rests on (1) awareness of its existence, (2) ultrasonography, and (3) selective biventricular and aortic angiography. It is possible that some of these patients might be candidates for ventriculo-aortic reconstitution.