RESUMEN
We performed mitral valvuloplasty for 25 months old infant with endocardial fibroelastosis (EFE) and 21 months old infant with endomyocardial fibrosis (EMF). These two patients showing good post operative cause, have been followed up during 10 and 1 years respectively. The EFE and EMF are severe and progressive restrictive cardiomyopathy of unknown etiology. Most of cases with EFE and EMF have an enlarged left ventricle with incompetent atrioventricular valve. The prognosis of these patient is usually poor. We believe that the surgical treatment in early phase may be able to improve heart failure and also to protect the progression of these disease. This case with EMF is the first report of successfull surgical treatment for the patients with severe congestive heart failure whithin one year after birth in Japan.