In total anomalous pulmonary venous return (TAPVR), the pulmonary veins incorrectly send blood to the heart's upper right chamber. That chamber is called the right atrium. As a result, oxygen-rich blood mixes with oxygen-poor blood, as shown in purple. In a typical heart, shown on the left, oxygen-rich blood flows from the pulmonary veins to the upper left chamber, also called the left atrium.
Mayo Clinic does not endorse companies or products. Advertising revenue supports our not-for-profit mission.
Check out these best-sellers and special offers on books and newsletters from Mayo Clinic Press.
Make a gift before July 31 and it can go twice as far to fight cancer.