Tetralogy of Fallot is a congenital heart defect that is characterized by a combination of four heart defects: Ventricular Septal Defect, Pulmonary Valve Stenosis, Right Heart Enlargement and the aorta growing from both ventricles instead of only from the left ventricle (left lower heart chamber). These defects lead to mixture of the oxygen-rich and oxygen-poor blood, result in poorly oxygenated blood being delivered to the rest of the body. Babies with tetralogy of fallot may experience intermittent episodes of extreme cyanosis (blue colored skin) during crying and feeding. These cyanotic attacks are serious and can be life-threatening. With early diagnosis and treatment, most children suffering from this condition are able to lead normal lives although they require regular medical care and have restrictions on exercise.