Overview, Causes, & Risk Factors
Transposition of the great arteries (TGA) is an abnormality of the
heart vessels that is present at birth, causing congenital heart disease. This is a serious heart defect that
usually requires open heart surgery for the baby to survive.
What is going on in the body?
In a normal heart, the main artery
of the body, called the aorta, is attached to the left side of the heart. The
main lung artery, called the pulmonary artery, is attached to the right side of
the heart. In the birth defect known as transposition of the great arteries, these arteries are reversed. When
this happens, the wrong blood goes to the wrong area.
Normally, blood with low
oxygen levels is sent to the lungs through the main lung artery to get oxygen.
Next, this blood is pumped out through the aorta to the rest of the body. In
TGA, blood with low oxygen levels is pumped through the aorta to the rest of
What are the causes and risks of the disease?
The cause of
TGA is unknown. Males are more commonly affected than females. Children born to
mothers with diabetes are also at
Symptoms & Signs
What are the signs and symptoms of the disease?
birth weight and size of a newborn with TGA is larger than normal. Symptoms and signs
difficulty breathing, rapid breathing, or shortness of breath
a bluish color of the skin, called cyanosis
signs of congestive heart
failure, which can include swelling in the legs and abdomen
heart murmurs, which are abnormal
low oxygen levels in the blood
Diagnosis & Tests
How is the disease diagnosed?
Diagnosis begins with the
physical exam. A chest X-ray may
reveal an abnormally shaped heart. A heart tracing, called an
electrocardiogram or ECG, may also be abnormal. The provider may order an echocardiogram, which uses ultrasound waves to see the beating heart. This test can show most of the defects in the heart and how they affect the heart's function.
A special procedure called a cardiac
catheterization may also be done. This procedure involves inserting a
tube though the skin and into a blood vessel, usually in the groin. The tube
can then be advanced through the blood vessel into the heart. A contrast agent
can be squirted through the tube and pictures taken while it is inside the
heart and main blood vessels. This can help better define the defects in the
heart. This procedure also allows tools to be passed through the tube and into
the heart. These tools can make special holes in the heart to improve
circulation until surgery can be done.
Prevention & Expectations
What can be done to prevent the disease?
In most cases,
nothing can be done to prevent TGA. A pregnant woman who has diabetes may be able to prevent TGA by controlling
her blood sugar levels during pregnancy.
What are the long-term effects of the disease?
effects of TGA are related to the exact nature and severity of the heart defects.
Children with TGA often have other heart defects. This can make treatment more
complicated and reduce the chance of long-term survival. Death is common in
those with TGA, especially when severe or complex defects of the heart are
present. In those who undergo surgery, congestive heart failure may occur years later and cause disability or
What are the risks to others?
TGA is not contagious and poses no risk to others.
Treatment & Monitoring
What are the treatments for the disease?
A baby with TGA needs to be
treated in a hospital that specializes in the treatment of children with congenital heart disease. Medications are
used to help keep the child alive until surgery can be done. Cardiac catheterization may also be used to
place a small hole in the heart to improve circulation. This is usually
done only to keep the child alive until surgery.
In some cases, open heart surgery may
be done hours after birth. In other cases, surgery may be delayed for a few
weeks. There are many different types of surgery, depending on the exact heart
defects that are present. The goal of surgery is to make the circulation as
close to normal as possible.
What are the side effects of the treatments?
many different medications that may be used before surgery. These may cause
allergic reactions, salt imbalances, or kidney damage. Surgery
may cause bleeding, infection, allergic reaction to anesthesia, and even death.
What happens after treatment for the disease?
The long-term outlook for a child with TGA usually depends on the severity of the heart defects before surgery. Children
will need close monitoring after surgery to make sure the heart is functioning
well. Heart medications may be needed after surgery. These medications can help
the heart pump better or stop irregular heartbeats, called arrhythmias.
How is the disease monitored?
A child with transposition of the great arteries will need long-term monitoring. It is important for the parents to watch for any return
of heart symptoms and report any change in the child's condition to
the healthcare provider.