[Subaortic stenosis due to antero-lateral muscular band, associated with ventricular septal defect and underdevelopment of the aortic arch. Anatomical features in three cases (author's transl)].

The pathological findings in three cases with ventricular septal defect and severe coarctation or tubular hypoplasia of the aortic arch are reported. The left ventricular outflow tract was partially obstructed by muscle situated on its antero-lateral wall. The haemodynamic relationship between this type of subaortic stenosis and aortic arch underdevelopment, due to unequal partitioning of the blood flow between the ascending aorta and the pulmonary artery during foetal life, is emphasized. The normal anatomy of the left ventricular infundibulum is described and some embryological hypotheses to explain this antero-lateral muscular band are forwarded.