Differential diagnosis of congenital heart disease

• Acyanosis + Increased pulmonary blood flow
  — Intracardiac left to right shunts = ventricular septal defect, atrial septal defect, AV canal, patent ductus arteriosus
  — Extracardiac left to right shunts = ateriovenous malformation in brain (Vein of Galen malformation) or liver (congenital hepatic hemangioma) or peripheral arteriovenous fistula
  — Failure (cardiomyopathies) = hypoxic cardiac injury (birth asphyxia, drowning), anomalous origin left coronary artery from pulmonary trunk, sepsis, endocardial fibroelastosis, glycogen storage disease (Pompe), viral myocarditis, adriamycin toxicity, fetal supraventricular tachycardia -> non-immune hydrops fetalis
• Cyanosis + Increased pulmonary blood flow
  — Admixture lesions – 5Ts+H = transposition of great arteries, total anomalous pulmonary venous return, truncus arteriosus, tricuspid atresia, single ventricle, hypoplastic left heart syndrome / double outlet right ventricle
• Cyanosis + Decreased pulmonary blood flow
  — Right to left shunts + right ventricular outflow obstruction – TET P = tetralogy of Fallot, Ebstein anomaly, tricuspid atresia, pulmonary atresia

Approach to the differential diagnosis of congenital heart disease:

• The clinical presence or absence of cyanosis correlated with the presence of increased or decreased pulmonary blood flow on CXR allows a congenital heart disease DDX to be generated
• In the ancient past, classic CXR signs of congenital heart disease could be used to help make the diagnosis. However, as these signs can take years to develop on a CXR, they are of less practical use today when congenital heart disease is diagnosed in-utero or in the immediate post-natal period
• Echocardiography is the means to rapidly obtain a diagnosis of congenital heart disease today