[Clinical aspects and physiopathology of fetal left heart hypoplasia. 2 case reports].

2 cases of congenital hypoplastic left heart syndrome are presented with regard to clinical signs and pathophysiology. The hypoplastic left heart syndrome consists of a hypoplastic left ventricle and absence or atresia of the aortic valve, associated with severe hypoplasia of the ascending aorta and various degrees of mitral valve hypoplasia. Infants are well developed at birth but are unable to maintain sufficient circulation after physiologic closure of the ductus arteriosus.