 Growth impairment is common in infants and children with congenital heart disease, most often in the presence of congestive heart failure andor cyanosis. Growth failure is noted in many infants with a single ventricle who manifest both cyanosis and heart failure that commonly persist after palliative surgery. Whether this impairment is related to persistent or progressive abnormalities in cardiac structure and function is not known. ACE-Is are widely used in the treatment of infants with severe congestive heart failure to improve cardiac function and somatic growth. The ability of an ACE-I to improve somatic growth in infants with a single ventricle has not been previously studied. 