Total anomalous pulmonary venous return
Total anomalous pulmonary venous return is a rare congenital heart defect in which all four pulmonary veins that carry oxygenated blood from the lungs to the heart are not properly connected to the left atrium. Instead, the pulmonary veins drain into other blood vessels or into the right atrium, which normally receives deoxygenated blood from the body. As a result, oxygenated blood cannot flow to the body efficiently, leading to symptoms such as cyanosis, difficulty breathing, poor feeding, and slow growth.
A patent foramen ovale, patent ductus arteriosus, or an atrial septal defect must be present, or else the condition is fatal due to a lack of systemic blood flow. Treatment requires surgery to reestablish the normal connections between the pulmonary veins and the left atrium. Infants with severe symptoms may require emergency surgery, while those with mild symptoms may be able to wait until they are a few months old.