Pediatric Total Anomalous Pulmonary Venous Return (TAPVR)

The normal heart has four chambers: two upper chambers called atria, which receive blood into the heart, and two lower chambers called ventricles, which pump blood out of the heart. Ordinarily, unoxygenated (blue) blood comes back from the body into the right atrium, moves into the right ventricle, and then is pumped out of the right ventricle through the pulmonary artery (the main artery to the lungs) to collect more oxygen. From the lungs, the now oxygenated (red) blood goes through four pulmonary veins to enter the left atrium, moves into the left ventricle, and is pumped out to the rest of the body through the aorta (the body’s main artery) – completing the cardiac cycle.

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Total anomalous pulmonary venous return (TAPVR) is a rare congenital (present at birth) condition in which the pulmonary veins that carry oxygenated blood from the lungs into the heart are anomalous – abnormal – and do not connect properly to the left atrium. Instead, as the baby’s heart forms during the first eight weeks of the mother’s pregnancy, the baby’s blood vessels connect to other veins that empty into the right atrium.

If one or more of the pulmonary veins connect in the left atrium (the correct place), but not all the veins, the condition is called PAPVR, or partial anomalous pulmonary venous return.

When all four pulmonary veins are connected improperly, the baby also develops a hole, known as an atrial septal defect or ASD, in the tissue between the two atria that allows the mixed blood – oxygenated and unoxygenated – to reach the left side of the heart and then be pumped out to the body. The ASD helps the newborn survive, but it also makes the baby’s heart have to work even harder to provide blood and oxygen to the rest of the body.

There are four types of TAPVR, defined by where the veins drain to the right atrium, be it from above, below or into the heart directly.

Sometimes, the abnormal veins become narrowed or blocked at the entrance before they enter the right atrium, making it hard for blood to move from the lungs to the heart. This is considered a cardiac emergency, requiring prompt surgery. As the blood from the lungs cannot return to the heart because of the blockage or narrowing, the pressure in the lungs climb, and it becomes difficult to breathe. Acid levels in the blood can rise, making the child very ill.

If there is no blockage, the baby may not be diagnosed for weeks or months, and only then will surgery be needed, generally within the infant’s first few months.

TAPVR is a congenital heart defect. It is so rare that TAPVR and PAPVR together affect only about one in 10,000 infants. While genes and environment can raise risks, TAPVR most often happens by chance.

TAPVR may be diagnosed during pregnancy with a fetal echocardiogram, which is a specialized ultrasound of the fetal heart. The affiliated physicians in the Fetal Cardiology Program at The Fetal Center will confirm a diagnosis and prepare a delivery plan for both mom and baby. A multidisciplinary team of specialists will also develop the baby's immediate care plan following delivery.

If TAPVR is not diagnosed in utero, and suspicion of a heart defect occurs after the baby is born, a pediatrician will refer the patient to a pediatric cardiologist to determine the diagnosis.

Signs of TAPVR include a bluish tint to lips, nails and skin, rapid breathing and sometimes a heart murmur – or whooshing sound – heard via a stethoscope. The worst cases are obvious at birth: Newborns may have difficulty breathing, an extreme bluish tint (from a lack of oxygen in the blood), a pounding heart, weak pulse, clammy skin, blood pressure issues or high acidity in the blood (acidosis).

The mildest cases may not reveal themselves for weeks or months via minor clues such as tiring easily. Doctors may order further testing after noticing rapid or difficult breathing, or poor growth.

The following tests may be utilized to find more details:

• Pulse oximetry, a small and painless gadget placed on a finger, which may reveal low oxygen rates from an inefficient heart.
• Chest X-rays, which create images of the heart and lungs, making major flaws visible, such as fluid buildup in the lungs.
• A cardiac echocardiogram (echo), using sound waves (ultrasound) to produce images of the heart and blood vessels’ structures on a screen. This reveals whether the heart is pumping properly.
• An electrocardiogram (EKG or ECG), a painless exam, which checks the heart’s electrical action to reveal damage or irregular rhythms, suggesting problems with the heart.
• A cardiac MRI (magnetic resonance imaging), using radio waves, magnets and a computer to form three-dimensional images of the heart, which can reveal structural abnormalities (such as an enlarged right ventricle).
• Cardiac catheterization, which involves a thin, long tube that is inserted into a blood vessel and guided into the heart. The doctor can see more details of a mixed TAPVR and widen the ASD or narrowed vessels at that time, to boost blood oxygen levels short-term.

Treatment of TAPVR is surgery, which consists of placing the patient on the heart-lung machine (cardiopulmonary bypass) and making the connection between the pulmonary veins and the left atrium. Fortunately, in most cases of TAPVR, all four pulmonary veins come to a central place (called a confluence) just behind the left atrium and a full anatomical repair can be achieved. However, after surgery, scar tissue may form around the connection between the pulmonary veins and the left atrium. If the scar tissue formation is severe enough, additional surgery may be required in the future.

If your child has a form of TAPVR that is obstructed (where the blood cannot get to the heart from the lungs), this may require an emergent surgical intervention. This is often performed when the child id only hours old. If the pulmonary veins are unobstructed, surgery can take place at an agreed upon elective date, usually at a few weeks of life.

Recovery from surgery is most closely related to the health of the lungs going into surgery. Although surgery for TAPVR has improved over the years, mortality from TAPVR repair is still fairly high, approximately 5-8% overall. This will vary greatly from child to child depending on the kind of TAPVR and the amount of pulmonary venous obstruction before surgery.

What Are the Long-Term Effects?

The most critically ill newborns may need to use a ventilator (breathing machine) after surgery overnight or for several days as their lungs recover. The baby will be observed closely – first in the intensive care unit and then elsewhere in the hospital – before being discharged..

What Follow-Up Care Is Needed?

The pediatric cardiologist will monitor the child long-term and may prescribe medication to prevent an infection of the heart’s lining (endocarditis) or an odd heartbeat (arrhythmia). Between 15% to 20% of TAPVR babies may need cardiac catheterization or surgery later in life to repair narrowed veins. They will be monitored by their cardiologist for the rest of their life, to make sure they do not develop an erratic heartbeat, clots, leaky valves or blocked blood vessels.

At Children’s Heart Institute at Children’s Memorial Hermann Hospital, patients with congenital or acquired heart disorders receive hands-on specialized care 24/7 from a team of affiliated physicians and specialty-trained nurses who aim to deliver the best possible outcomes.

Children’s Memorial Hermann Hospital was named one of the top children's hospitals nationally in Cardiology & Heart Surgery by U.S. News & World Report. In addition, Children’s Heart Institute is among the top congenital heart surgery programs in North America for patient care and outcomes, according to the Fall 2019 Society of Thoracic Surgeons (STS) Congenital Heart Surgery Database Report of 118 STS participating programs.

In collaboration with various subspecialties, the affiliated team provides comprehensive care for newborns, children and adolescents, with the ability to transition into adult congenital cardiac care. Team members have the experience and skills necessary to offer innovative treatment methods and specialized services, including, but not limited to:

• Biventricular repairs and biventricular conversions
• Congenital heart optimization
• Full repairs for complex congenital heart defects in newborns
• Hybrid catheterization and surgical procedures
• Minimally invasive transcatheter pulmonary valve (TPV) therapy
• Minimally invasive repairs
• Treatment for adult congenital heart disease
• Valve repairs and preservation

With the Level IV Neonatal Intensive Care Unit (NICU) and a dedicated Children’s Heart Institute Intensive Care Unit at Children’s Memorial Hermann Hospital, critical heart patients have access to quality, specialized care. By utilizing state-of-the-art techniques, the team at Children’s Heart Institute strives to offer patients with the most complex problems the greatest opportunity for a normal life.

If you have any questions, use the online tool below to help us connect with you. To refer a patient or schedule an appointment, please contact our clinic using the information below.

• Pediatric Cardiology Clinic
  The University of Texas Health Science Center Professional Building
  6410 Fannin, Suite 370
  Houston, TX 77030
  Phone: (713) 486-6755 (Appointment Line)
   
• Pediatric and Congenital Heart Surgery Clinic
  The University of Texas Health Science Center Professional Building
  6410 Fannin, Suite 370
  Houston, TX 77030
  Phone: (713) 500-5746
  CMHH-Heart@memorialhermann.org

The Children’s Heart Institute is a collaboration between the affiliated physicians at McGovern Medical School at UTHealth Houston and Children’s Memorial Hermann Hospital. Typically, patients are seen on an outpatient basis at a UT Physicians clinic with all inpatient procedures performed at Children’s Memorial Hermann Hospital.