Snapshot A neonatal boy is born to a 38-year-old mother with gestational diabetes. He seems to be tolerating feeds; however, in the first few days of life, his mother notices that his lips turn blue whenever he cries. It resolves when he stops crying. On physical exam, the physician notes central cyanosis while crying. The physician puts him in a knee-to-chest position, without any effect. Echocardiography is obtained, and he is found with a large ventricular septal defect and transposition of the great vessels. Introduction Clinical definition a congenital heart defect in which the aorta leaves the right ventricle and the pulmonary trunk leaves the left ventricle, resulting in the complete separation of the systemic and pulmonary circulations Etiology Failure of neural crest cells to migrate Pathogenesis failure of the aorticopulmonary septum to spiral results in complete separation of the systemic and pulmonary circulations infants survive only if a shunt between the two circulations exist to mix oxygenated blood into the systemic circulation patent ductus arteriosus (PDA) ventricular septal defect (VSD) atrial septal defect (ASD) patent foramen ovale (PFO) Associated conditions VSD coarctation of the aorta Epidemiology Demographics male > female present at birth most common cyanotic lesion presenting immediately after birth Risk factors maternal diabetes maternal smoking advanced maternal age Presentation Symptoms early and progressive cyanosis that does not correct with oxygen signs of heart failure tachypnea sweating poor feeding Physical exam cardiac loud and single S2 heart sound may have a soft systolic ejection murmur may have harsh holosystolic murmur if patients have VSD central cyanosis Imaging Radiography indication for all patients recommend views chest findings cardiomegaly egg-on-a-string appearance narrowed mediastinum Echocardiography indication performed as a diagnostic test most specific test findings pulmonary trunk arising from the left ventricle aorta arising from the right ventricle Differential Tetralogy of Fallot distinguishing factor tet spells (cyanosis) that are resolved when placed in knee-chest position Diagnosis Making the diagnosis based on clinical presentation and echocardiography in some cases, patients may be diagnosed prenatally with fetal echocardiography Treatment Medical prostaglandin E1 indication for all neonates mechanism of action maintains a patent ductus arteriosus for adequate lower extremity perfusion Operative balloon atrial septostomy (Rashkind procedure) indication for all patients performed for temporary mixing prior to definitive surgical repair arterial switch surgical repair indication for all patients as definitive treatment commonly performed in the first month of life Complications Heart failure Sudden cardiac death Prognosis Infants experience severe cyanosis and tachypnea as the ductus arteriosus closes in the newborn period Patients with large VSDs may not present with severe cyanosis they may only have cyanosis when the patient cries or feeds due to increased oxygen needs with activity