Transposition of the Great Arteries

What is transposition of the great arteries?

Transposition of the great arteries is a serious birth defect in which 2 large blood vessels leaving the heart are switched.

Normally, the pulmonary artery leaves the right ventricle and carries oxygen-poor (blue) blood to the lungs. The aorta leaves the left ventricle and carries oxygen-rich (red) blood to the body.

In babies with this birth defect, the pulmonary artery and aorta are reversed. The pulmonary artery leaves the left ventricle, and the aorta leaves the right ventricle.

This means oxygen-poor blood flows in a loop from the heart out to the body and back to the heart. Oxygen-rich blood flows in a loop from the heart to the lungs and back to the heart. So the baby’s body is not getting enough oxygen and appears blue.

Transposition of the Great Arteries

Reprinted with permission ©2009, American Heart Association, Inc.

Transposition of the Great Arteries at Seattle Children’s


  • Our Heart Center is the top-ranked cardiology and cardiac surgery program in the Northwest and among the best in the nation, according to U.S. News & World Report. With more than 40 pediatric cardiologists, we have experience diagnosing and treating every kind of heart problem.

    Our heart team has treated many children with transposition of the great arteries. In a typical year, we see 10 to 15 children with this condition. We have extensive experience with the surgery these patients require. We also have a pediatric cardiac anesthesia team and a Cardiac Intensive Care Unit to help care for children who undergo heart surgery.

    The Adult Congenital Heart Disease Program shared by Seattle Children’s and the University of Washington can help with care throughout your child’s life.

    Seattle Children’s has been treating children since 1907. Our team members are experts in their fields and in meeting the unique needs of children. For example, the doctors who give your child anesthesia (sedation) are board certified in pediatric anesthesiology. This means they have extra years of training in how to take care of kids. Our child life specialistsknow how to help children understand their illnesses and treatments in ways that make sense for their age.

    See our statistics and outcomes for arterial switch surgery, one of the treatments for transposition of the great arteries.

  • When you come to Seattle Children’s, a team of people will take care of your child. Along with your child’s heart doctor (cardiologist), you are connected with other providers, such as neonatologists, lung doctors (pulmonologists), nurses, child life specialists, social workers and others, if their expertise is needed.

    We work together to meet all of your child’s health needs and help your family through this experience. We’ll discuss treatments in ways you can understand and involve you in every decision.

    Read more about the supportive care we offer.

Symptoms of Transposition of the Great Arteries

Most babies with transposed great arteries are very blue (cyanotic) soon after birth due to a low oxygen level. They may also seem to be working hard to breathe and have trouble feeding.

If their ductus arteriosus is helping oxygen-rich and oxygen-poor blood mix so that some oxygen can get to their body, their symptoms will get worse as the ductus begins to close (this is a normal step after birth). If they have a patent ductus arteriosus (ductus that does not close on its own), some oxygen-rich blood will continue to get through.

If they have a relatively large atrial septal defect or ventricular septal defect, their symptoms may be less severe because this hole provides a path for some oxygen-rich blood to get from their lungs to the rest of their body.

Diagnosing Transposition of the Great Arteries

To diagnose this condition, your doctor will examine your child and use a stethoscope to listen to their heart.

The doctor will ask for details about your child's symptoms, their health history and your family health history.

Your child will also need tests that provide information about how their heart and blood vessels look and work. These may include: 

Treatment Options for Transposition of the Great Arteries

Babies with transposed great arteries need surgery soon to change their blood flow so oxygen-poor blood goes to their lungs and oxygen-rich blood goes to their body.

  • Doctors use 1 of these methods for surgery:

      • They switch the transposed arteries to the correct locations in the heart. They connect the pulmonary artery to the right ventricle and the aorta to the left ventricle. The coronary arteries, which bring blood to the heart muscle, also need to be moved so that they remain connected to the aorta. This is the most common method used now. It is called the arterial switch operation. (See our statistics and outcomes for arterial switch surgery.)

    Arterial Switch

    Reprinted with permission ©2009, American Heart Association, Inc.

    • They leave the transposed arteries in place, but create a tunnel within the atria that directs oxygen-poor blood to the left ventricle (so it can flow to the pulmonary artery to the lungs) and oxygen-rich blood to the right ventricle (so it can flow out the aorta to the body). This method is used rarely now. There are 2 versions of this operation, named after the surgeons who developed them, called the Mustard or Senning procedure. 

    Intra-Atrial Baffle

    Reprinted with permission ©2009, American Heart Association, Inc.

  • Before your baby has surgery, they may need other steps. These may include: 

    • Getting medicine (prostaglandin) to keep their ductus arteriosus from closing
    • Having cardiac catheterization to enlarge their patent foramen ovale (a small hole between the atria that normally closes shortly after birth) using a balloon 

    These steps may allow doctors to delay surgery until your baby grows larger and is more stable, which can improve the outcome of surgery.

  • If your baby has other heart defects, like atrial septal defect or ventricular septal defect, they will typically be repaired during the same surgery.

Adult Congenital Heart Disease Program

To meet your child’s long-term healthcare needs, we have a special Adult Congenital Heart Disease Program to transition your child to adult care when they’re ready.

Contact Us 

Contact the Heart Center at 206-987-2515 to request an appointment, a second opinion or more information.

Providers, see how to refer a patient.