Total anomalous pulmonary venous return (TAPVR) is a heart defect where all (total) of the pulmonary veins do not connect to the left atrium.
The pulmonary veins are four blood vessels that bring blood from the lungs to the left atrium (upper chamber) of the heart. Partial anomalous pulmonary venous return (PAPVR) is a heart defect where one or more of a child’s pulmonary veins do not connect normally to the left atrium. When TAPVR or PAPVR occurs, the veins are re-directed to another blood vessel that eventually connects to the heart.