Total anomalous pulmonary venous return

Anomalous pulmonary venous connection is a rare cyanotic congenital heart defect in which all four pulmonary veins are malpositioned and make anomalous connections to the systemic venous circulation. Normally, pulmonary veins return oxygenated blood from the lungs to the left atrium where it can then be pumped to the rest of the body. A patent foramen ovale, patent ductus arteriosa or an atrial septal defect must be present, or else the condition is fatal due to a lack of systemic blood flow.