Infants with congenital heart disease (CHD) are usually born with a normal weight but develop malnutrition over time, and about 20-50% of these children are usually malnourished. Malnutrition in these patients is multifactorial. To compensate for the increased need for infants and children with CHD, an increase in their caloric intake has been suggested. However, these patients may not be able to receive enough to meet the increased needs and catch-up growth. One of the suggested solutions in these patients to compensate for inadequate food intake is to increase the caloric density of milk or formula. For this purpose, the use of special formulas with higher calorie density or enrichment of normal formula or breast milk using special enrichment formula could be suggested. In the present study, the effect of increasing calorie intake by increasing the concentration of normal formula in comparison with formula with standard concentration on weight gain and other anthropometric indices of CHD patients with malnutrition will be compared.

Inclusion Criteria:

• Infant and children 6 to 24 months with CHD undergoing repair surgery
• Malnutrition (weight for age Z score ≤ -1)

Exclusion Criteria:

• Allergy to cow's milk protein
• Preterm infant or infant weighing less than 2500 grams at birth
• Children with chromosomal disease (Down, Turner)