Physical Activity and Cognitive Development in Children

Inclusion Criteria: * Congenital Heart Diseases (CHD) Cohort: All children with congenital cyanotic cardiac diseases scheduled for congenital cardiac surgery who are older than 30 months of age. * Non-CHD, Surgical Cohort: All children 30 months or older who are undergoing non-cardiac surgery at Columbia University Medical Center (CUMC), including pediatric general surgery, urological surgery, ear, nose and throat (ENT) surgery, plastic surgery and eye surgery. These children will be recruited before surgery. * Non-surgical cohort: 1. Sibling of children of CHD patients within 12 months in age, and 30 months of age or older. 2. Relatives of CHD patients of the same gender within 12 months in age and 30 months of age or older. 3. Best buddies of CHD children within 12 months in age and 30 months of age or older. 4. Children who are matched by age ±6 months who are 30 months of age or older, gender, level parental education and language spoken at home Exclusion Criteria: 1. Children with known chromosomal syndromes, or known syndromes including but not limited to DiGeorge, Trisomy 21, WIlliams, Noonan and Turner. 2. Children with known physical disabilities. 3. Children with known history of central nervous system (CNS) injury including stroke, birth asphyxia, seizure disorder, intraventricular hemorrhage. 4. Children with abnormal neurological exam by a pediatric physician or nurse practitioner, and confirmed by a pediatric neurologist. 5. Children with tricuspid regurgitation on echocardiography or on cardiac angiography that is moderate or greater. 6. Children with moderate or greater decrease in ventricular function on echocardiography or on cardiac angiography. 7. Children with baseline room air oxygen saturation below 80%. 8. Children who are treated for dysrhythmias or are pacemaker-dependent. 9. Children with history of prematurity. (Non-surgical cohort) 10. Children with history of more than one episode of hospitalization. (Non-surgical cohort)