Total anomalous pulmonary venous connection (TAPVC)

What is it?

TAPVC is a rare congenital heart defect. It accounts for 1% of all congenital heart defects.

It can also be referred to as TAPVR (Total Anomalous Pulmonary Venous Return) or TAPVD (Total Anomalous Pulmonary Venous Drainage)

Normally, the pulmonary veins connect to the left atrium. They bring oxygen rich blood from the lungs back to the heart. In TAPVC, the pulmonary veins do not enter the left atrium. Instead they drain into the heart by way of an abnormal (anomalous) connection.

There are different types of TAPVC and these are based on where the pulmonary veins connect.

Supracardiac TAPVC: the most common type. The pulmonary veins form a connection above the heart and drain into the superior vena cava (SVC). The SVC brings oxygen poor blood back from the upper part of the body to the right side of the heart. This means that oxygen poor blood and oxygen rich blood are entering the heart into the right atrium.

Cardiac TAPVC: the pulmonary veins meet behind the heart and enter the right atrium or the coronary sinus. 

Infracardiac TAPVC: the pulmonary veins form a connection below the heart and drain into the inferior vena cava (IVC). The IVC brings oxygen poor blood back from the lower part of the body into the right side of the heart. This means that oxygen rich poor blood and oxygen rich blood are entering the heart into the right atrium.

Mixed TAPVC: a combination of supracardiac, infracardiac and cardiac connections.All types of TAPVC have an atrial septal defect (ASD). An atrial septal defect (or ASD for short) is a hole in the heart – specifically in the atrial septum (the dividing wall between the right and left atria of the heart). The atria are the upper chambers of the heart. The ASD will allow some of the oxygenated blood that has entered the right atrium from the pulmonary vein to go across to the left atrium and out to the body. 

How can it be spotted?

TAPVC is most commonly detected after birth by echocardiogram.

Shortly after birth, the baby will display the following signs:

These signs will prompt the health professional to perform further investigations such as pulse oximetry testing and an echocardiogram

How can it be treated?

Depending on the type of TAPVC, some babies will need to have the medicine prostaglandin started to keep the duct open. This will enable blood to reach the body until surgery can take place.

Babies with TAPVC will need surgery. When the surgery takes place will depend on the general condition of the baby and the specific structure of the abnormal connections.

The surgeons will connect the pulmonary veins to the left atrium and they will also close off any abnormal connections. This will restore normal blood flow through the heart. Sometimes, an atrial balloon septostomy is needed in babies to improve their blood oxygenation to help stabilise them prior to the corrective surgery. Before birth, all babies have a hole between the right atrium and the left atrium. A balloon septostomy involves inserting a fine tube – a catheter – through the belly button or groin. This is guided into the heart and through the hole between the atria. A balloon on the end of the catheter is inflated and gently pulled back so that the hole is made bigger. This means there is more mixing of oxygenated and deoxygenated blood.

General advice/info for the future

The long-term outcome after surgical repair of TAPVC is very good as the repair means that there is a normal circulation through the heart. Children who have had a TAPVC repair will need regular check-ups by a paediatric cardiologist. 

Some may need repeat tests like echocardiogram, ECG and sometimes cardiac Magnetic Resonance Imaging (MRI) scans. The aim of these tests is to monitor your child’s heart function so that any future and treated quickly. 

As your baby will have had open heart surgery, they will have a scar down the middle of the chest, and there will be small scars where drain tubes were used, but these will fade over time.