Total anomalous pulmonary venous connection (TAPVC) is a rare heart defect.

In a normal heart, the blood flows in from the body to the right atrium. It then goes into the right ventricle through the tricuspid valve. The blood travels to the lungs through the pulmonary valve to pick up fresh oxygen. Next, the blood returns to the left atrium, goes into the left ventricle, and goes out to the rest of the body.

Heart Chambers and Valves
heart anatomy
Copyright © Nucleus Medical Media, Inc.

Blood Flow Through the Heart
Copyright © Nucleus Medical Media, Inc.

With TAPVC, the pulmonary veins that return oxygenated blood from the lungs connect to the right side of the heart, instead of the left atrium. This leads to the mixing of oxygenated and de-oxygenated blood. The body tissue does not receive as much oxygen as it is supposed to. TAPVC can be mild to severe. There can be a range of connection problems. Other heart problems may be present, as well.

TAPVC is a congenital defect. This means that the heart forms incorrectly when the baby is in the womb. It is not known exactly why the heart develops this way in some babies.