What Is Total Anomalous Pulmonary Venous Return?
Total anomalous pulmonary venous return (TAPVR) is a congenital (present at birth) heart defect. Due to abnormal development of the fetal heart during the first 8 weeks of pregnancy, the vessels that bring oxygen-rich (red) blood back to the heart from the lungs are improperly connected. Normally, oxygen-poor (blue) blood returns to the right atrium from the body, travels to the right ventricle, then is pumped through the pulmonary artery into the lungs where it receives oxygen. Oxygen-rich (red) blood returns to the left atrium from the lungs through four pulmonary veins. It then passes into the left ventricle, and is pumped through the aorta out to the body. In TAPVR, the four pulmonary veins are connected somewhere besides the left atrium. There are several possible places where the pulmonary veins can connect. The most common connection is to a blood vessel that brings oxygen-poor (blue) blood back to the right atrium, usually the superior vena cava. In TAPVR, oxygen-rich (red) blo
