balloon valvuloplasty was carried out in 23 infants and children ranging in age from one month to eleven years and in two adults at the age of 22 and 50 years , respectively , with a systolic pressure gradient across the pulmonary valve of more than 50 mm hg or , in the presence of pressure gradients between 40 and 50 mm hg , in association with a right ventricular pressure of at least 60 % of that of the systemic pressure .
C0021270
infants
C0008059
children