Transposition of the Great Arteries

What is transposition of the great arteries?

Transposition of the great arteries (or vessels) is a rare issue where the main arteries that move blood out of your heart are in the wrong places. They also connect to your heart in the wrong places. It’s a congenital (present at birth) condition.

The two reversed (transposed) arteries are:

• The main pulmonary artery, which carries blood into your lungs.
• The aorta, the artery that carries blood from your heart to the rest of your body.

Your arteries are part of your circulatory system, which helps blood flow through your body. Unlike most arteries, which bring oxygen-rich blood to your body, your pulmonary arteries carry oxygen-poor blood.

Levo-transposition (l-TGA) type

With this type, a baby’s aorta is to the left of their pulmonary artery. In addition to the two major arteries, the lower section of your baby’s heart is also reversed. Blood without oxygen goes to your baby’s lungs and blood with oxygen goes to their body. But the wrong pumping chamber gets them there. This type is less common but also less harmful because blood goes where it should. Less than 1% of babies who have congenital heart conditions have the l-transposition type of TGA.

Dextro-transposition (d-TGA) type

With this type, a baby’s aorta is to the right of their pulmonary artery. About 5% to 7% of babies with congenital heart conditions have this type of TGA. This type is the main focus of this article.

When your baby’s pulmonary artery and aorta connect to the wrong parts of their heart, it affects how blood travels. It can make it difficult for enough oxygen to reach your baby’s organs. This is because your baby’s blood skips going to their lungs for oxygen. Blood that has oxygen doesn’t travel throughout their body to deliver oxygen. This happens in babies with the d-transposition type.

Holes between your baby’s upper (atrial septal defect or ASD) or lower (ventricular septal defect or VSD) heart chambers may be present at birth, as well. Although they’re abnormal, these congenital conditions may help blood without oxygen to mix with blood that contains oxygen.

That amount of oxygen isn’t enough, though. Your baby will need procedures to ensure that enough oxygen reaches their whole body. While nobody likes to think about a baby having surgery, it’s the best solution for the long term. Surgeons have been doing these operations for decades — with high survival rates.

What are the symptoms of transposition of the great arteries?

Newborns with d-TGA have symptoms of cyanosis (low oxygen) and may also have heart failure. Transposition of the great arteries symptoms include:

• Trouble breathing.
• Weak pulse.
• Difficulty feeding.
• Pounding heart.
• Skin or whites of their eyes appear bluish (in light-skinned babies) or grayish (in dark-skinned babies).

When do symptoms of transposition of the great vessels appear?

In a baby with the “d” type of TGA heart problem, signs appear soon after birth. Their severity depends on whether oxygen-rich blood can reach the rest of your baby’s body by “mixing” in the upper chambers of their heart.

Babies with d-TGA who have a large enough atrial septal defect may have less severe symptoms. That’s because ASD makes a hole for some oxygenated blood to get pumped into their body. Babies will also have a fetal blood vessel, called a patent ductus arteriosus, that allows mixing.

Some newborns don’t show symptoms right away because small openings around their hearts haven’t closed yet. Once the holes close, symptoms appear, and your baby requires immediate medical attention.

What causes transposition of the great arteries?

Researchers don’t know what causes transposition of the great vessels. Like other congenital heart conditions, it might result from a genetic variation (change) or exposure to toxins during pregnancy.

A baby may be more likely to be born with TGA if, during pregnancy, you:

• Had gestational diabetes.
• Had rubella (German measles).
• Were exposed to certain pesticides or herbicides.
• Took certain antiseizure medications.

How is transposition of the great arteries diagnosed?

Your healthcare provider may diagnose transposition of the great vessels during pregnancy. Prenatal tests check for congenital conditions.

If your provider notices a concern during a prenatal ultrasound, they may recommend a fetal echocardiogram. This noninvasive test is a detailed ultrasound. It can confirm a d-TGA diagnosis.

If providers don’t diagnose d-TGA during your pregnancy, they typically diagnose it within your baby’s first week of life.

What tests will be done to diagnose transposition of the great arteries?

To diagnose transposition of the great arteries, providers can use:

• Echocardiogram (Echo).
• Electrocardiogram (EKG).
• Newborn pulse oximetry screening to measure oxygen levels (often part of newborn care).
• Chest X-ray.
• Cardiac catheterization, a more invasive test your provider can use if other tests don’t offer an answer regarding the coronary arteries.
• Computed tomography (CT) scan.

How is transposition of the great arteries treated?

Babies born with the “d” type of transposition of the great arteries need surgery to survive. Many babies with d-TGA have surgery within the first week of life. Surgeons perform an arterial switch procedure, which involves switching the positions of your baby’s aorta and pulmonary artery. It restores a typical pathway for blood to flow through their heart and out to their body. If your child has a VSD, a surgeon will repair it at the same time using a synthetic patch.

Your child’s care team may use other treatments to delay major surgery for a short time until your baby can handle the procedure better. These include:

• Prostaglandin: This medication can keep the ductus arteriosus open. This is a blood vessel your baby uses before birth, but it closes after birth because they usually don’t need it anymore. Keeping it open allows oxygen-rich blood to flow through your child’s body.
• Septostomy procedure: A balloon atrial septostomy uses a catheter (thin tube) to widen the natural opening between the atria (right and left upper chambers in the heart). This minimally invasive procedure allows blood to mix so it can collect oxygen and deliver it to your child’s body.

Can transposition of the great arteries be prevented?

There’s no known way to prevent transposition of the great arteries. But good prenatal care matters. Be sure your immunizations are up to date, take a multivitamin and keep prenatal appointments.

If you have a history of congenital heart conditions in your biological family, talk to your provider. They may recommend genetic testing and counseling before pregnancy.

What can I expect if I have transposition of the great vessels?

While surgery doesn’t cure d-transposition of the great arteries, most people with the condition can lead full, healthy lives. But people with this congenital condition need lifelong care. A cardiologist (heart specialist) monitors your progress to help you manage complications.

What is the survival rate for transposition of the great arteries?

The survival rate after an arterial switch surgery is more than 95%. This survival rate stands even 25 years later.

How can my child best live with transposition of the great vessels?

Your child can live a full life after treatment for transposition of the great arteries. For either type of the condition, their heart needs lifelong follow-up care, including:

• Regular appointments with a cardiologist with expertise in this condition.
• Medications.
• Regular, noninvasive heart function tests, which may include EKGs, Holter monitors, exercise stress tests and echocardiograms.

Many cardiologists don’t recommend competitive sports after d-transposition surgery. You and your child should talk to your pediatrician and cardiologist. Together, you can make a decision that’s best for your child’s health.

Many people who’ve had d-TGA surgery have had successful pregnancies. Talk to your healthcare provider and a cardiologist before getting pregnant. You may need to find a center that offers both high-risk obstetrical services and expertise in adult congenital heart disease.

What types of heart complications might my child have?

After transposition surgery, people have a higher risk for other heart problems. Potential heart complications include:

• Loss of heart muscle or heart valve function.
• Valve leakage.
• Heart rhythm problems.
• Enlargement of their aortas.
• Problems with their re-implanted coronary arteries.

Will my child need more heart surgeries?

Yes, your child may need more surgery later. The most common procedures are to restore their heart’s rhythm after a VSD repair or to repair heart valves.

Is there a risk for endocarditis?

Endocarditis is an infection that happens when bacteria enter your heart. It’s more common in people with heart conditions, like TGA. People who had transposition surgery may need to take antibiotics before dental procedures.

How do I take care of my child?

In addition to caring for your child’s heart issues, you may need to address possible differences in their brain development. Children who had an arterial switch operation may have ADHD or need special education services.

When should I see my healthcare provider?

See a healthcare provider if your baby has:

• Trouble breathing.
• Weak pulse.
• Bluish or whitish skin around their mouth.

If you had transposition surgery as a child, you need routine care and evaluation throughout your life. You should see a cardiologist with experience caring for adults with congenital heart disease.

What questions should I ask my healthcare provider?

If your child has transposition of the great arteries, you may want to ask your provider:

• Will my child need surgery right away?
• What procedure is best?
• What kind of follow-up care will my child need?
• Will they need a second surgery?
• Are there any restrictions on their activities?
• How can I best care for my child after surgery?

If you had surgery for this condition as a child, ask your provider:

• Will I need another surgery?
• What type of monitoring do I need?
• Are there any restrictions on my activities?
• Can I have a baby?

A note from Cleveland Clinic

Having a baby with a congenital heart condition isn’t in any new parent’s plans. But your baby’s healthcare providers can help guide you through the decisions ahead. It’s helpful to remember that providers have been treating babies with TGA for many years. Be an advocate for your child and their future. Don’t be afraid to ask questions about anything you’re unsure about.