Congenitally Corrected Transposition of the Great Arteries (CCTGA)
Before you begin reading about this heart defect, please read the explanation of how the normal heart works for a basic understanding of its structure and function.
- What is congenitally corrected transposition of the great arteries (CCTGA)?
- What are the symptoms?
- How is it diagnosed?
- What are the treatment options?
- What kind of follow-up care is required?
What is congenitally corrected transposition of the great arteries (CCTGA)?
In a normal heart, the left-side pumping chamber (left ventricle) sends blood to the entire body, whereas the right-side ventricle pumps blood only a short distance, to the lungs. The left ventricle is built stronger than the right ventricle, because it has to work harder.
In congenitally corrected transposition of the great arteries (CCTGA), the heart twists abnormally during fetal development, and the ventricles are reversed: The stronger left ventricle pumps blood to the lungs and the weaker right ventricle has the harder chore of pumping blood to the entire body.
This can cause problems, particularly for the right ventricle, which must work harder than it was meant to. For many patients, in the long run, the ability of the right ventricle to continue to function effectively will determine how well they are.
There are several problems that co-exist in many patients with CCTGA and affect how well they do and what kind of treatment or surgical repair may be suitable.
The most common associated lesions are:
- A ventricular septal defect (VSD): a hole between the two pumping chambers of the heart.
- A blockage on the way of the blood to the lungs (pulmonic stenosis).
- An abnormal valve that tends to leak (Doctors call this an “Ebstein-like” tricuspid valve.)
- Hearts use an electrical impulse to make their muscle contract. In CCTGA the electrical conduction system can get “blocked” and patients may require an artificial pacemaker.
CCTGA is a rare heart defect. Only 0.5 – 1 percent of all people with heart defects have CCTGA. This means there are about 5,000 – 10,000 people in the United States with this condition.
In this condition both ventricles (pumping chambers) are reversed and the arteries coming off them are inverted as well. The end result is paradoxically a blood flow pathway which is normal. This led to the confusing term “corrected” for a complex malformation in which the heart is far from being normal.
What are the symptoms?
People with CCTGA experience a wide variety of symptoms, depending on the associated defects they have. There are sick newborns, with low oxygen level, who need care immediately after birth, and there are healthy people who can live a normal life for many years, without any intervention.
In one case, a woman was diagnosed with CCTGA at age 83 having had five children. On the other hand, some babies born with CCTGA die in infancy. Many people with CCTGA have no or few symptoms as children and young adults, but develop problems as they age. Outcomes are better for those born without additional heart defects.
CCTGA is often not diagnosed until adolescence or adulthood, when problems develop because of the leaky heart valve, abnormal electrical conduction in the heart, or inability of the right ventricle to continue the hard work of pumping blood to the entire body.
The symptoms may include fainting from the block in the electrical conduction, or fatigue from inability of the heart to pump enough blood to the body and backward flow through the leaky valve.
How is it diagnosed?
Diagnosis may require some or all of these tests.
- echocardiogram (also called “echo” or ultrasound) – sound waves create an image of the heart
- chest X-ray
- electrocardiogram (ECG) – a record of the electrical activity of the heart
- cardiac MRI – a three-dimensional image that shows the heart’s abnormalities
- cardiac catheterization – a thin tube is inserted into the heart through a vein and/or artery in either the leg or through the umbilicus (“belly button”)
Echocardiogram and cardiac MRI are most commonly used in the diagnosis of CCTGA.
What are the treatment options?
Treatment varies according to the type and severity of symptoms and associated defects. In some patients, especially those that have no additional heart defects, there may not be a need to do anything.
For patients that do need surgery the type of operation will vary according to the associated defects. There are several operations used in this condition, including:
- Closure of the hole in the heart (VSD) and insertion of a tube (conduit) between the heart and the lungs. The conduit may need to be exchanged at a later date, requiring another operation.
- Leaving the VSD open and repairing the heart as if it had only one pumping chamber (ventricle). This is called a Fontan repair and involves routing the veins that bring blood without oxygen back to the heart to go directly to the lungs to pick up oxygen, bypassing the heart.
- Double switch operation. Surgeons use patches to redirect the veins coming back to the heart, and they attach the arteries leaving the heart to the opposite ventricle than they were connected to when the child was born. This is a very complex operation, with which there is not much long-term experience. Young children seem to do better with this operation than adult patients.
Any of the above operations may also have to include replacement of the leaky tricuspid valve with an artificial valve, and insertion of a pacemaker.
Because those operations are complex and difficult they are best performed in centers with large patient volume, resources and experience.
What kind of follow-up care is required?
CCTGA is a complex heart condition. Some related complications begin and can be treated early in childhood, but others develop later in life. CCTGA requires life-long care by a cardiologist with expertise in congenital heart disease.
Our pediatric cardiologists follow patients until they are young adults. The care is then transitioned to a special service we have for adults with congenital heart disease (ACHD). The American College of Cardiology has recommended that CCTGA patients be seen regularly at regional ACHD centers.
We will help patients transition their care to our ACHD program, or to a cardiologist with congenital heart disease expertise in another location.
The Philadelphia Adult Congenital Heart Center, a joint program of The Children's Hospital of Philadelphia and the University of Pennsylvania, meets the unique needs of adults who were born with heart defects.
Because of enormous strides in medicine and technology, today many children with heart conditions go on to lead healthy, productive lives as adults.
Contact the Cardiac Center at The Children's Hospital of Philadelphia for a second opinion or for more information.
Reviewed by: Alex Davidson, MD
Date: January 2010
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