In total anomalous pulmonary venous return, where do the four pulmonary veins connect?

In total anomalous pulmonary venous return (TAPVR), the four pulmonary veins, which normally carry oxygenated blood from the lungs to the left atrium, instead connect abnormally to the right atrium or to a structure that drains into the right atrium. This abnormal connection occurs due to a failure in the normal fetal development of the pulmonary veins.

As a result, oxygen-rich blood that should be entering the left atrium is redirected back into the right atrium. This leads to a mix of oxygenated and deoxygenated blood being pumped into the systemic circulation, which can result in significant physiological challenges.

Understanding this condition is crucial, as it may require surgical intervention to reroute the pulmonary veins correctly so that oxygenated blood can flow to the left atrium and then into the left ventricle, ultimately reaching the rest of the body.