Total anomalous pulmonary venous return is a congenital heart disease (present at birth) in which none of the four veins that drain blood from the lungs to the heart is attached to the left atrium (upper chamber of the heart).

The cause of total anomalous pulmonary venous return (TAPVR) is unknown.

In normal circulation, blood picks up oxygen in the lungs and then returns to the left atrium. It then flows to the left ventricle, through the aorta, and around the body. In TAPVR, oxygenated blood returns to the right atrium instead. From there it goes to the right ventricle, through the pulmonary artery and back to the lungs. In other words, blood simply circles to and from the lungs and never gets out to the body.

If the infant is to live, a large atrial septal defect (ASD) or patent foramen ovale (passage between the left and right atria) must exist to allow oxygenated blood to flow to the left side of the heart and rest of the body.

The severity of this condition depends on whether the pulmonary veins are obstructed. There are four subtypes of TAPVR, based on the location of the veins' connection back to the heart. In one type, the veins run into the abdomen, passing through a muscle (diaphragm). This muscle squeezes the veins and narrows them, causing the blood to back up into the lungs. This type causes symptoms early in life.

The infant may appear to be critically ill and may display the following symptoms:

• Lethargy
• Poor feeding
• Rapid breathing
• Poor growth
• Frequent respiratory infections
• Cyanosis (blue discoloration of the skin)

Note: In some cases no symptoms may be present in infancy or early childhood.

• ECG shows signs of enlargement of the ventricles (ventricular hypertrophy).
• X-ray of the chest shows a normal to small heart with fluid in the lungs.
• Echocardiogram usually defines the attachment of pulmonary vessels.
• Cardiac catheterization can provide definitive diagnosis by showing abnormal attachments of the blood vessels.

Early complete surgical repair is indicated. In surgery, the pulmonary veins are connected to the left atrium and the defect between the right and left atrium is closed.

If left untreated, there is a high rare of death by age 1. With surgery, early repair gives excellent results if there is no blockage of the pulmonary veins at the new connection into the heart.

A small number of patients later develop irregular, fast heart rhythms (arrhythmias) that need medication.

• Heart failure
• Breathing difficulties
• Lung infections
• Pulmonary hypertension

This condition may be apparent at the time of birth. However, symptoms may not be present until later.

Call your health care provider if you notice symptoms of TAPVR -- prompt attention is required!

There is no known way to prevent TAPVR.