Partial anomalous pulmonary venous return (PAPVR) is a rare heart defect that's present at birth (congenital heart defect). This condition may also be called partial anomalous pulmonary venous connection (PAPVC).

In this heart defect, some but not all of the lung blood vessels (pulmonary veins) are attached to the wrong place in the heart.

Normally, oxygen-rich blood goes from the lungs to the upper left heart chamber (left atrium) and then flows through the body. In PAPVR, an abnormal connection of veins sends blood into other blood vessels and into the upper right heart chamber (right atrium), where it mixes with oxygen-poor blood. As a result, extra oxygen-rich blood flows back to the lungs.

Some people with this heart defect also have a hole between the upper heart chambers (atrial septal defect), which allows blood to flow between the upper heart chambers (atria). Other congenital heart defects also may occur. A child born with Turner syndrome has an increased risk of PAPVR.

If PAPVR occurs with other heart defects, it may be diagnosed soon after birth. If the condition is mild, it may not be diagnosed until adulthood.

The doctor will perform a physical exam and listen to the heart with a stethoscope to check for a heart murmur.

An echocardiogram is generally used to diagnose total anomalous pulmonary venous return. This test uses sound waves to create images of the heart in motion. An echocardiogram can show pulmonary veins, holes in the heart and the size of the heart chambers. It can also measure the speed of blood flow.

Other tests such as an electrocardiogram (ECG or EKG), a chest X-ray, a magnetic resonance imaging (MRI) scan or a computerized tomography (CT) scan may be done if more information is needed.

If you aren't having symptoms or if there isn't much mixing of oxygen-rich and oxygen-poor blood, surgery may not be needed to treat this condition.

Surgery may be needed if there is a large amount of oxygen-rich and oxygen-poor blood mixing in the heart, or if the condition causes many lung infections. If surgery for another heart condition is needed, surgeons may repair this heart defect at the same time.

To repair this defect, surgeons generally reconnect the pulmonary veins to the left atrium. Surgeons will also close the hole in the heart if there is one.

Children will need regular follow-up appointments with pediatric cardiologists. Adults with this heart defect will need lifelong care and regular follow-up appointments with doctors trained in congenital heart conditions (adult congenital cardiologists) to monitor for any changes in their condition.