Preoperative assessment in patients with congenital heart disease differs according to the age and the cardiac defect of the patient. In most cases blood tests and echocardiography are often sufficient whereas in complex lesions a more extensive assessment is required, including cardiac catheterization, MRI or CT-Scan. Some tests are also routinely included in the preoperative evaluation of neonates which are not necessary in older children. In each case surgical decisions are made in common with pediatric cardiologist and pediatric cardiac surgeons, based on history, physical exam, lab results and cardiac status of the patient.