In total anomalous pulmonary venous connection (TAPVC), the pulmonary veins that bring oxygen-rich (red) blood from the lungs back to the heart aren't connected to the left atrium. Instead, the pulmonary veins drain elsewhere.
The most common site of drainage is either to a large vein (the superior vena cava) which brings the blue blood from the upper part of the body or to the right atrium directly or indirectly. Therefore, no blood comes back to the left atrium and survival depends on the presence of a hole between the right and left atrium to allow blood to get to the left atrium, then the left ventricle and out to the body.
Thus, many of the babies are blue due to the “blue” blood from the body mixing with the oxygen-rich “red” blood from the lungs.
The primary feature of this defect is the finding of cyanosis. Symptoms such as difficulty breathing, rapid breathing, difficulty feeding and poor growth may occur as well.
There may be an abnormal murmur on physical examination. The diagnosis is confirmed with an echocardiogram.
This defect should be surgically repaired in early infancy. The pulmonary veins are reconnected to the left atrium and the atrial septal defect is closed.
The risks of open-heart surgery always include bleeding, infection and the need for cardiopulmonary bypass. Special risks include residual obstruction to the pulmonary veins as they are reconnected to the heart, injury to the hearts normal pacemaker and rhythm abnormalities.
When surgical repair is done in early infancy, the long-term outlook is very good. Still, lifelong follow up is suggested to make certain that any remaining problems, such as an obstruction in the pulmonary veins or irregularities in heart rhythm, are treated properly. It's important to make certain that a blockage doesn't develop in the pulmonary veins or where they're attached to the left atrium. Heart rhythm irregularities (arrhythmias) also may occur at any time after surgery. Preventive measures against bacterial endocarditis may be required for life.