Transposition of the Great Arteries (TGA) in Children
Overview
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.
Causes
Most of the time, the cause of TGA isn’t known.
Symptoms
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.
Diagnosis
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.
Pulse oximetry
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.
Chest X-ray
A chest X-ray shows the size and
shape of the heart and lungs.
Electrocardiogram (ECG)
This test records the electrical
activity of the heart. It also shows abnormal rhythms (arrhythmias or dysrhythmias)
and spots heart muscle stress.
Echocardiogram (echo)
An echocardiogram uses sound
waves to make a moving picture of the heart and heart valves. This test is used to
diagnose 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 called a 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 the heart more
clearly. This test measures your child’s pressure and oxygen levels in the four
chambers of the heart, the pulmonary artery, and aorta. Your child will get medicine
to help them relax and prevent pain (sedation).
Cardiac MRI
This test uses magnets and radio waves to make images of the heart, blood vessels,
and surrounding structure.
Treatment
All children with a TGA will need
to have surgery to fix it. Your baby will likely be admitted to the intensive care
unit.
Medical management
At first, your baby may get the
following care:
- Supplemental oxygen or a ventilator
(a machine that helps do the work of breathing for the baby)
- Different types of medicine given
by 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 until surgery can be done.
Balloon atrial septostomy
Your child may have a procedure
called a balloon atrial septostomy. This may be done during cardiac catheterization
or at the bedside using an echocardiogram. This procedure uses a balloon catheter
to
make or enlarge an atrial septal defect. It allows oxygen-rich blood and oxygen-poor
blood to mix and makes it easier for oxygen-rich blood to reach the rest of the
body.
Surgery
Typically, in the first two
weeks of life, your baby will need surgery for TGA. This procedure is called
an arterial switch. Your child’s surgeon will connect the aorta and pulmonary artery
to their normal ventricles. The surgeon will also have to move the coronary arteries.
The surgeon will also fix any other heart problems, such as a ventricular septal
defect, which is a hole in the heart.
Complications
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
Living with
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 to Call a Healthcare Provider
If your child has trouble breathing or any new symptoms, call their
healthcare provider.
Key Points
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.