Heart Chambers and Valves  
heart anatomy

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Blood Flow Through the Heart  

Copyright © Nucleus Medical Media, Inc.


Tricuspid atresia is an abnormal development of the right side of the heart. It includes a missing valve between the upper and lower chamber and a smaller than normal lower chamber. Tricuspid atresia can make it difficult for your heart to efficiently pump blood to the lungs to get oxygen. Some may also have holes in the wall between the left and right side of the heart. The holes allow oxygen-rich and oxygen-poor blood to mix.



Tricuspid atresia develops when the baby is in the womb. It is not known exactly why some hearts develop this way.


Risk Factors  

Factors that increase the risk for congenital heart defects like tricuspid atresia include:

  • Family history of congenital heart defect
  • Chromosomal disorder such as Down syndrome
  • Previous pregnancy with fetal heart abnormalities or miscarriage
  • Conditions during pregnancy, such as:
    • Being infected with a virus
    • Having poorly controlled diabetes
    • Drinking alcohol
    • Taking certain medicines


Symptoms may include:

  • Blue or pale grayish skin color
  • Fast breathing
  • Sweating
  • Poor feeding/poor weight gain
  • Fatigue


Tricuspid atresia may be diagnosed before birth.

After birth, the doctor may