Total Anomalous Pulmonary Venous Return (TAPVR)

What is total anomalous pulmonary venous return?

Anatomy of the heart, normal

Total anomalous pulmonary venous return (TAPVR) is a congenital (present at birth) heart defect. Due to abnormal development of the fetal heart during the first eight weeks of pregnancy, the vessels that bring oxygen-rich (red) blood back to the heart from the lungs are improperly connected.

Normally, oxygen-poor (blue) blood returns to the right atrium from the body, travels to the right ventricle, then is pumped through the pulmonary artery into the lungs where it receives oxygen. Oxygen-rich (red) blood returns to the left atrium from the lungs through four pulmonary veins. It then passes into the left ventricle, and is pumped through the aorta out to the body.

In TAPVR, the four pulmonary veins are connected somewhere besides the left atrium. There are several possible places where the pulmonary veins can connect. The most common connection is to a blood vessel that brings oxygen-poor (blue) blood back to the right atrium, usually the superior vena cava.

Anatomy of a heart with total anomalous pulmonary venous return

In TAPVR, oxygen-rich (red) blood that should return to the left atrium, the left ventricle, the aorta, and then the body, instead mixes with the oxygen-poor (blue) blood flowing into the right side of the heart. This situation by itself will not support life, because there is no way for oxygen-rich (red) blood to be delivered to the body.

Other heart defects are often associated with TAPVR, and they actually help the infant with total anomalous pulmonary venous return to live until surgical intervention is possible:

  • An opening in the atrial septum will allow blood from one side to mix with blood from another, creating "purple" blood with an oxygen level somewhere in-between that of the oxygen-poor (blue) and the oxygen-rich (red) blood.

  • Patent ductus arteriosus will also allow mixing of oxygen-poor (blue) and oxygen-rich (red) blood through the connection between the aorta and pulmonary artery. The "purple" blood that results from this mixing is beneficial, providing at least a little oxygen to the body.

Total anomalous pulmonary venous return occurs equally in boys and in girls.

Prevention & Risk Treatment

Prevention & Risk Treatment

What causes total anomalous pulmonary venous return?

The heart is forming during the first eight weeks of fetal development. The problem occurs during this time, allowing the pulmonary veins to be attached incorrectly.

Why is TAPVR a concern?

Babies with this heart defect cannot supply oxygen-rich (red) blood to the body after birth. Without an additional heart defect that allows mixing of oxygen-poor (blue) and oxygen-rich (red) blood, such as an atrial septal defect, infants with TAPVR will have a mixture of oxygen-rich (red) and oxygen-poor (blue) blood circulating through the right heart and back to the lungs—a situation that is fatal:

Two fetal "shunts," or connections present in the fetal circulation, remain open for a short while after birth.

  • The foramen ovale, an opening between the right atrium and the left atrium, will allow some of the blood returning to the right atrium to flow into the left side of the heart, and on out to the body.
  • The ductus arteriosus, connecting the aorta to the pulmonary artery, allows some blood to mix between the two vessels, allowing more partially oxygenated blood to go to the body.

Another problem that occurs with TAPVR is that too much blood flows through the blood vessels in the lungs, since the pulmonary veins add extra blood back in to the circulation on the right side of the heart. The lungs become stressed by this extra blood flow, and can eventually become damaged from it.

What are the symptoms of total anomalous pulmonary venous return?

The obvious indication of TAPVR is a newborn who becomes cyanotic (blue coloring of the skin, lips, and nailbeds) in the first days of life after the maternal source of oxygen (from the placenta) is removed. The degree of cyanosis is related to the degree of obstruction of the anomalous pulmonary veins, and the size of the foramen ovale that allows the red and blue blood to mix.

Babies with large atrial or ventricular septal defects, allowing a mixture of oxygen-rich (red) and oxygen-poor (blue) blood to enter the left heart and go to the body, may have less cyanosis and fewer symptoms at birth. Babies who have a large foramen ovale or a ductus arteriosus that remains open for a while may also present with symptoms a few days or weeks after birth.

The following are the other most common symptoms of total anomalous pulmonary venous. However, each child may experience symptoms differently. Symptoms may include:

  • Rapid breathing
  • Labored breathing
  • Rapid heart rate
  • Cool, clammy skin
  • Lethargy 
  • Poor feeding

The symptoms of total anomalous pulmonary venous may resemble other medical conditions or heart problems. Always consult your child's doctor for a diagnosis.



How is transposition of the great arteries diagnosed?

A pediatric cardiologist and/or a neonatologist may be involved in your child's care. A pediatric cardiologist specializes in the diagnosis and medical management of congenital heart defects, as well as heart problems that may develop later in childhood. A neonatologist specializes in illnesses affecting newborns, both premature and full-term.

Cyanosis is the major indication that there is a problem with your newborn. Your child's doctor may have also heard a heart murmur during a physical examination. In this case, a heart murmur is a noise caused by the turbulence of blood flowing through the openings that allow the blood to mix, such as the ventricular septal defect or patent ductus arteriosus. 

Diagnostic testing for congenital heart disease varies by the child's age, clinical condition, and institutional preferences.  Some tests that may be recommended include the following:

  • Chest X-ray. A diagnostic test that uses invisible X-ray beams to produce images of internal tissues, bones, and organs onto film.
  • Electrocardiogram (ECG or EKG). A test that records the electrical activity of the heart, shows abnormal rhythms (arrhythmias), and detects heart muscle stress.
  • Echocardiogram (echo). A procedure that evaluates the structure and function of the heart by using sound waves recorded on an electronic sensor that produce a moving picture of the heart and heart valves. 
  • Cardiac catheterization. A cardiac catheterization is an invasive procedure that gives very detailed information about the structures inside the heart. Under sedation, a small, thin, flexible tube (catheter) is inserted into a blood vessel in the groin, and guided to the inside of the heart. Blood pressure and oxygen measurements are taken in the four chambers of the heart, as well as the pulmonary artery and aorta. Contrast dye is also injected to more clearly visualize the structures inside the heart.
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