What is tricuspid atresia?

Tricuspid atresia is a congenital (present at birth) heart defect that occurs when the tricuspid valve of the heart is not properly formed. The tricuspid valve lies between two of the chambers of the heart (the right atrium and right ventricle). In tricuspid atresia, there is solid tissue in place of the tricuspid valve. This sheet of tissue blocks blood flow from the right atrium to the right ventricle. Because of this blockage, the right ventricle usually is small and underdeveloped.

Blood in a baby with this defect flows from the upper right chamber (right atrium) to the upper left chamber (left atrium) of the heart through a hole in the septum, the wall between the chambers. The hole can be a heart defect (atrial septal defect) or an enlarged natural opening (foramen ovale). The foramen ovale is a hole that should close soon after a baby is born. If there is no atrial septal defect, a surgeon may need to create a foramen ovale to allow blood flow.

In some babies with tricuspid atresia, there is a hole between the heart’s two lower chambers (ventricular septal defect). In babies with this defect, blood can flow through the hole and into the right ventricle, which will pump the blood into the lungs.

When tricuspid atresia is present, a sufficient amount of blood is not able to flow through the heart and into the lungs. As a result, a baby with this defect has blood that does not obtain oxygen as the blood in a normal heart would. The lungs are not able to provide the rest of the body with its required oxygen.

What are the risk factors for tricuspid atresia?

Risk factors are traits that make a person more likely to develop a disease or condition. Risk factors do not mean that a person will definitely develop a condition, only that the person is more likely to do so. Risk factors for tricuspid atresia include:

  • Down syndrome
  • A parent who had a congenital heart defect
  • A mother who had a viral illness (including German measles) during early pregnancy
  • A mother who drank too much alcohol while pregnant
  • A mother whose diabetes is not properly controlled
  • A mother who used some kinds of medications, such as anti-seizure or acne medications, during pregnancy

What is the cause of tricuspid atresia?

Although there are known risk factors for tricuspid atresia, the exact causes are not known. Congenital heart diseases develop while the baby is in the womb and heart development is taking place.

What are the symptoms of tricuspid atresia?

In most cases, babies born with tricuspid atresia have symptoms within a week after being born. A baby with tricuspid atresia can show the following symptoms:

  • Becoming tired easily
  • Skin and lips that are bluish in color (cyanosis)
  • Shortness of breath
  • Slow growth
  • Heart murmur (unusual heart sounds)

In addition, some babies with this condition can develop heart failure symptoms. These include:

  • Rapid weight gain from retaining fluids
  • Swelling in the abdomen
  • Swelling in the legs, ankles, and feet
  • Weakness and fatigue
  • Irregular or fast heartbeat

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