Transposition of the great arteries (TGA)

TGA explained

Transposition of the great arteries (TGA) is a type of congenital heart disease, which means it’s something you’re born with. In most cases, it's not known why you're born with a condition. Some people with TGA are also born with other congenital heart diseases like ventricular septal defect (VSD) and coarctation of the aorta (COA).

TGA is where the two main arteries in your heart are swapped around. This means:

• Your pulmonary artery, which takes blood to the lungs to pick up oxygen, is where your aorta should be.
• Your aorta, which takes blood high in oxygen from your heart to your body, is where your pulmonary artery should be.
• Your pulmonary artery may also be narrowed (stenosis).

The swapping of the pulmonary artery and aorta causes a few problems, like:

• The blood that’s pumped from your heart to your lungs to get oxygen goes around in a circle instead of into your body to deliver oxygen.
• Blood that’s pumped from your heart to the rest of your body to deliver oxygen goes around in a circle instead of back to the lungs to get more oxygen.
• If your pulmonary artery is narrowed, blood does not flow as well as it should.

Because of these issues, only a small amount of blood high in oxygen is moving around your body. Oxygen is only able to move into the body by:

• A blood vessel (called the ductus arteriosus, or ‘duct’) that closes shortly after you’re born.
• If you have another congenital heart defect that lets oxygen move around the heart like an atrial septal defect (ASD) or VSD.

TGA symptoms

When you’re born with TGA, the symptoms you have as a baby can include:

• blue or grey skin (cyanosis)
• having little energy
• shortness of breath
• a weak pulse
• long periods of crying
• difficulty feeding or gaining weight.

If your child has any of these symptoms, speak to a healthcare professional as soon as possible. They'll be able to help and advise you on what to do.

TGA symptoms as an adult

The symptoms that you have as an adult depend on you and your condition. Factors that can affect the symptoms you have include:

• whether you were born with other conditions like ASD or VSD
• the type of surgery you had to fix TGA.

Learn more about the complications you may have as an adult.

What is cyanosis?

Cyanosis is when your skin and lips turn blue or grey due to low levels of oxygen. It can be a side effect or symptom of some congenital heart diseases.

It happens with TGA because a small amount of blood high in oxygen is moving around your body.

TGA diagnosis

TGA is sometimes diagnosed before you’re born during an ultrasound (a test that creates detailed images of a baby during pregnancy).

If it’s not picked up before you’re born and your doctor thinks you may have TGA, they’ll send you for tests to find out. The tests may include:

• a chest X-ray
• an echocardiogram
• an electrocardiogram (also called ECG or EKG)
• oxygen level measurement.

Your doctors may ask you to have a certain type of heart catheterisation to assess your heart in more detail. Speak to your doctor if you have questions about this test, other tests or diagnosis.

TGA pre-treatment

TGA is treated using surgery within the first few weeks of your life. Before your TGA is repaired, healthcare professionals will try to get more blood high in oxygen moving around your body. They’ll do this using medicine or a balloon septostomy.

Medicine

Your healthcare professional may give you a medicine called prostaglandin. This helps to keep your duct (ductus arteriosus) open and let blood move around your body. A side effect of this drug can be that it limits your breathing, so you may need the support of a ventilator (a machine that helps you breathe).

Balloon septostomy

This is a procedure that’s usually done in the first few days of your life. It’s where a balloon is used to open a hole in your heart to help blood high in oxygen move around your body.

Within a few weeks after the balloon septostomy, you’ll have an operation to treat your TGA.

• Learn more about the procedure with the NHS.

TGA treatment

There are a few options to treat your TGA, all of which involve major surgery. The arterial switch operation is now the most common procedure. Before that was available, the atrial switch was most common. Sometimes the atrial switch or a Rastelli procedure are done when it’s not possible to do an arterial switch.

Arterial switch operation

• Your surgeon switches your aorta and pulmonary artery back to their normal positions. Your surgeon also makes sure the blood flow to your heart is fixed.

Atrial switch (Mustard or Senning)

• Your surgeon makes a tunnel (called a baffle) between the two sides of your heart, letting blood move around your heart.
• The procedure is called a ‘Senning’ if the tunnel is made from part of your heart (tissue). It’s called a ‘Mustard’ if the tunnel is man-made (synthetic).

Rastelli

• Your surgeon makes a man-made tunnel between the bottom two chambers of your heart. This lets blood move from the left ventricle to the aorta.
• Your surgeon adds a tube (called a conduit) from the right ventricle to the pulmonary artery. This lets blood go around (bypass) the narrowed pulmonary artery.

For each of these surgeries, you’ll be given a general anaesthetic. This means you’ll be asleep and will not feel any pain during the procedure. You'll also have a scar along your breastbone (the long flat bone in the middle of your chest) afterwards.

Your healthcare professional will decide which surgical treatment option is best for you depending on you and your condition. If you're the parent of a child or someone in need of this treatment, speak with your healthcare professional if you have any questions. 

• Read about others who have had heart surgery and how they wear their scars with pride.

Congenitally corrected transposition of the great arteries (CCTGA)

CCTGA is a similar and less common congenital heart disease to TGA. It’s where both your right and left ventricles are swapped and your aorta and pulmonary artery are swapped. Since both the upper and lower connecting parts of your heart are swapped, blood still flows well.

Sometimes CCTGA is diagnosed in childhood if you’re born with another congenital heart disease or noticed by accident during tests. It often goes unnoticed until adulthood because your heart's working well enough.

• Learn more about CCTGA with the NHS.

Living with TGA

You’ll be offered appointments at a congenital heart disease specialist clinic, where they check your heart for the rest of your life. Even if you feel well, going to these appointments is important because there may be changes in your heart before you get symptoms.

Most people living with repaired TGA can live a normal life. However, as you get older, problems can start to happen that may need to be treated. This usually depends on:

• if you were born with other conditions like ASD or VSD
• the type of surgery you had to fix TGA.

These factors affect how well you are as an adult and what you’re able to do when it comes to things like exercise, work and family planning. It’s best to talk to your healthcare professional or team if you have any questions about living with TGA.

Complications of TGA

As you get older, it’s common to have problems with your heart. You’re more likely to have issues if your TGA was repaired by an atrial switch or Rastelli procedure.

The complications can include:

• narrowing (stenosis) of the pulmonary artery
• leaky heart valves (regurgitation)
• baffle narrowing or leaking
• conduit narrowing or leaking
• heart rhythm problems (arrhythmias)
• weakening of your heart muscle and heart failure.

You may need more surgeries in the future to fix these problems, like a leaking valve or narrowed pulmonary artery. Speak to your healthcare professional or team if you have any questions about having more treatment.

Heart Helpline and more support

If you have any questions or concerns, speak to your healthcare team. You can talk to them about anything, even if it feels uncomfortable or embarrassing. Most people feel much better once they do.

Here are some other ways you can get support:

• Learn more about congenital heart disease.
• Hear other stories of people living with congenital heart disease.
• Learn more about TGA with the NHS.
• Speak to our cardiac nurses on Heart Helpline by phone, callback, email or online chat (Monday to Friday, 9am to 5pm).
• Talk with others with heart conditions by joining a support group or online community.
• Contact us to talk to our customer care advisors, find your local BHF shop and for any comments, compliments and complaints you may have.