Transposition of the Great Arteries (TGA)
What is transposition of the great arteries?
Transposition of the great arteries (TGA) is a type of congenital heart defect. This
means that your baby is born with it. In this condition, the large blood vessels
that carry blood from the heart to the lungs and body aren’t connected as they should
- The aorta is connected to the right ventricle. It should be connected to the left
- The pulmonary artery is connected to the left ventricle when it should be connected
to the right ventricle.
In TGA, the following occurs:
- Oxygen-poor (blue) blood is sent to the body.
- Oxygen-rich (red) blood returns to the lungs.
This is the opposite of a normal heart.
Babies cannot 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, such as obstruction of blood flow from the right ventricle to the aorta, and
variations in the course of the coronary arteries. Other heart problems such as an
atrial or ventricular septal defect may allow some oxygen-rich blood to be sent to
your baby’s body. In addition, some normally present aspects of your baby's heart
may remain intact to allow oxygen- rich blood reach your child's body. Normally, these
connections would close shortly after birth. \
Heart defects that can happen with TGA include:
- An opening in the ventricular septum, called a ventricular septal defect (VSD). This
is a hole between the 2 lower chambers of the heart. This allows oxygen-poor and oxygen-rich
blood to mix.
Normally present aspects of your baby's heart that remain tact include:
What causes TGA?
Most of the time, the cause of TGA isn’t known.
What are the symptoms of TGA?
Most babies with TGA have blue skin color (cyanosis) in the first hours or days of
Other symptoms 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 his or her healthcare provider for a diagnosis.
How is TGA diagnosed?
A healthcare provider may spot TGA in a baby during an ultrasound in pregnancy. But
a baby usually isn’t diagnosed until after birth. A healthcare provider may suspect
TGA if your baby has bluish skin. Or your child's healthcare provider may suspect
this issue when he or she hears an abnormal sound (heart murmur) when listening to
your child's heart with a stethoscope.
After birth, if your child has signs of TGA, a pediatric cardiologist or neonatologist
will check him or her. A pediatric cardiologist is a doctor with special training
to treat heart problems in babies and children. A neonatologist is a doctor with special
training to treat problems in newborns. These doctors will be part of your baby’s
heart care team.
Your child’s doctor may do tests to confirm the diagnosis. The tests your child has
depends on his or her age and condition, and the doctor’s preferences.
For this test, a probe is placed on your child's finger or toe. It measures the level
of oxygen in the blood, if it is below a certain level, this may be a sign of TGA.
A chest X-ray shows the size and shape of the heart and lungs.
This test records the electrical activity of the heart. It also shows abnormal rhythms
(arrhythmias or dysrhythmias) and spots heart muscle stress.
An echo uses sound waves to make a moving picture of the heart and heart valves. This
test may show TGA.
Cardiac catheterization (cardiac or heart cath)
A cardiac catheterization gives detailed information about the structures inside the
heart. In this test, a small, thin, flexible tube (catheter) is put into a blood vessel
in your child’s groin. Then the healthcare provider guides it to your child’s heart.
Your child’s healthcare provider will inject your child with contrast dye to see his
or her heart more clearly. This test measures your child’s blood pressure and oxygen
in the 4 chambers of the heart and the pulmonary artery and aorta. Your child will
get medicine to help relax and prevent pain (sedation).
How is TGA treated?
Treatment will depend on your child’s symptoms, age, and general health. It will also
depend on how severe the condition is.
All children with a TGA will need to have surgery to fix it. Your baby will likely
be admitted to the intensive care unit (ICU).
At first, your baby may get the following care:
- Supplemental oxygen or a machine that allows breathable air to move in an out of the
lungs (ventilator). This helps with breathing.
- Medicine given into a vein (intravenous or IV). This will help your baby’s heart and
lungs work better.
- A medicine called prostaglandin E1. This is used to keep the ductus arteriosus open.
This allows blood to flow through the heart.
Your child may have a test called a balloon atrial septostomy. This is done during
cardiac catheterization. This test makes it easier for oxygen-rich blood to reach
the rest of the body by creating or enlarging an atrial septal defect which allows
oxygen-rich blood and oxygen-poor blood to mix.
In the first few months of life, your baby will need surgery for TGA. This procedure is
called an arterial switch. Your child’s surgeon will move the aorta and pulmonary
artery to their normal places. The surgeon will also have to move the coronary arteries.
The doctor will also fix any other heart problems.
What are the complications of TGA?
Complications of untreated TGA include:
- Heart valve problems
- Heart muscle problems or problems with the arteries that supply blood to the heart
- Abnormal heart rhythm
- Heart failure
- Lung problems
Living with TGA
Your child will stay in the hospital until surgery. Your child’s healthcare team will
tell you how to care for your baby before you leave the hospital. He or she 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 his or her heart doctor for checkups. Your child may need additional surgeries
or cardiac cath in the future.
Your child's doctor may give him or her antibiotics before surgeries or dental procedures.
This is to prevent infections. Your child may also need to limit physical activity
and avoid certain sports. Ask your child’s heart doctor what activities are safe for
When should I call my child's healthcare provider?
If your child has trouble breathing or any new symptoms, call his or her healthcare
Key points about TGA
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 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 to see his or her heart doctor for checkups and may require
more surgery in the future.
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 provider after office hours. This is important
if your child becomes ill and you have questions or need advice.