by EBSCO Medical Review Board
(Single Ventricle Lesions—Child)


Single ventricle anomalies are rare heart conditions that can happen in a growing fetus. In a normal heart, the two ventricles work by collecting blood and pumping it to the lungs or the rest of the body. With this condition, one of the ventricles does not develop properly. The defect can be mild to severe. Other heart problems may also be present.

Examples of single ventricle anomalies are:

  • Tricuspid atresia—tricuspid valve does not develop
  • Pulmonary atresia—pulmonary valve does not develop
  • Hypoplastic left heart syndrome—left side of the heart does not develop properly
  • Double inlet left ventricle—large left ventricle and small right ventricle
Heart Chambers and Valves
heart anatomy
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These problems are caused by congenital defects. This means that the problem develops in the womb and a baby is born with it. It is not known exactly why this happens.

Risk Factors

Specific risk factors are often unclear, but they may be:

  • A family history of congenital heart defect
  • Other heart defects
  • Certain chromosomal disorders
  • Environmental exposure to chemicals that cause birth defects


Problems may be:

  • Blue or pale grayish skin color
  • Fast breathing
  • Rapid heartbeat
  • Sweating
  • Poor feeding
  • Poor weight gain


The doctor will ask about your child’s symptoms and health history. A physical exam will be done. It will focus on the heart. This problem may be suspected if the doctor hears a heart murmur.

Blood tests will be done.

Images may be taken of your child's body. This can be done with:

Your child's heart function may be tested. This can be done with:


The goal of treatment is to improve heart function and blood flow. Choices are:

  • Medicines to keep blood flowing through a connection that normally closes a few days after birth
  • Surgery to:
    • Place a shunt to restore connections between the heart and lungs as well as the heart and rest of the body
    • Place a band around the pulmonary artery if there is too much blood flow
    • Reroute blood flow through the heart and lungs through a series of surgeries

Children with severe problems may need a heart transplant.

Lifelong heart monitoring will be needed after treatment.


There are no known guidelines to prevent this heart problem.


American Heart Association 

Family Doctor—American Academy of Family Physicians 


Canadian Cardiovascular Society 

Heart and Stroke Foundation of Canada 


Rao PS. Consensus on timing of intervention for common congenital heart diseases: part II - cyanotic heart defects. Indian J Pediatr. 2013 Aug;80(8):663-674.

Single ventricle anomalies and Fontan circulation. Cincinnati Children’s Hospital website. Available at: Accessed March 10, 2021.

Single ventricle defects. American Heart Association website. Available at: Accessed March 10, 2021.

Single ventricle heart defects. Children’s Hospital of Philadelphia website. Available at: Accessed March 10, 2021.

Tricuspid atresia. EBSCO DynaMed website. Available at: Accessed March 10, 2021.

Revision Information

  • Reviewer: EBSCO Medical Review Board Kari Kassir, MD
  • Review Date: 12/2020
  • Update Date: 03/10/2021