What is an anomalous pulmonary venous return?
Anomalous pulmonary venous return (APVR) is a rare heart defect that occurs when the pulmonary veins fail to form normally while the baby is in the mother’s womb. It comprises <1% of all congenital heart defects. The cause of the problem is not known. In the normal heart, there are four pulmonary veins that bring red blood back from the lungs to the heart’s left upper chamber (the left atrium). Two of the veins bring red blood from the right lung and two bring red blood from the left lung. In a baby with anomalous pulmonary venous return, one or more of the pulmonary veins returns to the right atrium instead of the left atrium. If all the pulmonary veins are affected, the diagnosis is total anomalous pulmonary venous return (TAPVR). When a child has anomalous pulmonary veins, the abnormal veins take one of three possible pathways.
