What is transposition of the great arteries in children?

Transposition of the great arteries (TGA) is a type of heart defect that your baby is born with (congenital). In this condition, the two arteries that carry blood out of the heart aren’t connected as they should be. They are reversed (transposed).

In TGA, the following occur:

• The aorta is connected to the right ventricle. It should normally be connected to the left ventricle.

• The pulmonary artery is connected to the left ventricle when it should normally be connected to the right ventricle.

This means that:

• Oxygen-poor (blue) blood is sent to the body instead of to the lungs.

• Oxygen-rich (red) blood is sent to the lungs instead of going to the body.

This is the opposite of a normal heart.

Babies can't live with this condition unless they get treatment.

TGA may occur on its own. Or your child may also have other heart problems in addition to TGA. These might include blockage of blood flow from the right ventricle to the aorta, or variations in the course of the coronary arteries. Other heart problems, such as a hole in the wall between the upper chambers of the heart (atrial septal defect) or a hole in the wall between the lower chambers of the heart (ventricular septal defect), may allow some oxygen-rich blood to mix with oxygen-poor blood that is sent to your baby’s body. Also, some parts of your baby's heart may stay intact to allow oxygen-rich blood to reach your child's body. Normally, these connections would close shortly after birth.

What causes TGA in a child?

Most of the time, the cause of TGA isn’t known.

What are the symptoms of TGA in a child?

Many babies with TGA have a bluish or gray color to the skin (cyanosis) in the first hours or days of their lives.

Other symptoms that can occur include:

• Fast breathing

• Trouble breathing

• Fast heart rate

• Poor feeding

The symptoms of TGA may be similar to symptoms of other conditions. Make sure that your child sees their healthcare provider for a diagnosis.

How is TGA diagnosed in a child?

If your child has signs of TGA after birth, a pediatric cardiologist or neonatologist will check your child. A pediatric cardiologist is a healthcare provider with special training in treating heart problems in babies and children. A neonatologist is a healthcare provider with special training in treating problems in newborns. These providers will be part of your baby’s heart care team.

Your child will likely have tests to confirm the diagnosis. The tests your child has depend on your child's age and condition, and the provider’s preferences.

How is TGA treated in a child?

All children with a TGA will need to have surgery to fix it. Your baby will likely be admitted to the intensive care unit.

What are possible complications of TGA in a child?

Complications of untreated TGA include:

• Heart valve problems

• Heart muscle problems or problems with the arteries that supply blood to the heart muscle

• Abnormal heart rhythm 

• Heart failure

• Lung problems

• Death

How can I help my child manage TGA?

Your child will stay in the hospital until after surgery. Your child’s healthcare team will tell you how to care for your baby before you leave the hospital. They may also give you information about home healthcare for your baby, if you need it.

Most children who have surgery for this condition will grow and develop normally. Ask your child's healthcare provider about your child’s outlook. Your child will still need to see their providers for checkups. Your child may need additional surgeries or cardiac catheterizations in the future.

Your child may need to have antibiotics before surgeries or dental procedures. This is to prevent infections. Your child may also need to limit physical activity and stay away from certain sports. Ask your child’s cardiologist about what activities are safe for your child.

When should I call my child's healthcare provider?

If your child has trouble breathing or any new symptoms, call their healthcare provider.

Key points about TGA in children

In TGA, your child’s aorta is connected to the right ventricle, and the pulmonary artery is connected to the left ventricle. This is the reverse of a normal heart.

• A newborn with TGA will usually have gray or bluish skin color in the first days of life.

• All children with a TGA will need to have surgery to fix it.

• Most children who have surgery for this condition will grow and develop normally. Your child will still need checkups and may need more surgery in the future.

Next steps

Tips to help you get the most from a visit to your child’s healthcare provider:

• Know the reason for the visit and what you want to happen.

• Before your visit, write down questions you want answered.

• At the visit, write down the name of a new diagnosis and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you for your child.

• Know why a new medicine or treatment is prescribed and how it will help your child. Also know what the side effects are.

• Ask if your child’s condition can be treated in other ways.

• Know why a test or procedure is recommended and what the results could mean.

• Know what to expect if your child does not take the medicine or have the test or procedure.

• If your child has a follow-up appointment, write down the date, time, and purpose for that visit.

• Know how you can contact your child’s healthcare provider after office hours. This is important if your child becomes ill and you have questions or need advice.