Transposition of the Great Arteries (TGA)
Before you begin reading about transposition of the great arteries, please read the explanation of how the normal heart works for a basic understanding of its structure and function.
- What is transposition of the great arteries?
- What are the symptoms of TGA?
- How is TGA diagnosed?
- What are the treatment options for TGA?
- What kind of follow-up care is required for TGA?
What is transposition of the great arteries (TGA)?
View Large Transposition of the Great Arteries IllustrationTransposition of the great arteries (TGA) is a complex congenital heart defect in which the two large arteries that carry blood out of the heart are connected to the heart abnormally:
- The aorta is attached to the right-sided pumping chamber (ventricle), instead of the left.
- The pulmonary artery is attached to the left-sided pumping chamber (ventricle), instead of the right.
In the animation above, doctors describe the
structure of a heart with transposition of the
great arteries.
Normally, blood flows in this pattern: body » right side of heart » lungs » left side of heart » back to body. The pulmonary artery carries blood from the right side of the heart to the lungs, and the aorta carries blood from the left side of the heart to the body. In children with TGA, the normal pattern of flow does not exist, and the body doesn't get enough oxygenated blood.
What are the symptoms of TGA?
The symptoms of TGA include:
- Blue or purple tint to lips, skin and nails (cyanosis)
- Rapid breathing
- Difficulty feeding; poor appetite and poor weight gain
How is transposition of the great arteries diagnosed?
Transposition of the great arteries may be diagnosed before birth, with fetal echocardiogram (ultrasound). Our Fetal Heart Program will prepare a plan for delivery and care immediately after birth.
Sometimes TGA is diagnosed when an infant is a few hours or days old, and in some cases, infants may not have visible symptoms for weeks or months. Pediatricians from other hospitals refer newborns to the Cardiac Center when they notice symptoms or abnormal values on laboratory testing such as pulse oximetry.
Diagnosis of TGA may require some or all of these tests:
- Echocardiogram (also called "echo" or ultrasound) - sound waves create an image of the heart
- Electrocardiogram (ECG) - a record of the electrical activity of the heart
- Chest X-ray
- Pulse oximetry - a non-invasive way to monitor the oxygen content of the blood
- 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")
- Cardiac MRI - a three-dimensional image shows the heart's abnormalities
What are the treatment options for TGA?
The animation above shows balloon
atrial septostomy. Transposition of the great arteries is unpredictable. Approximately one-third of newborns with the condition will require an urgent intervention, called a balloon atrial septostomy (BAS), within hours after birth. This procedure, which creates or enlarges a hole between the upper chambers of the heart to allow blood to mix, was developed at The Children’s Hospital of Philadelphia in the 1960s.
For babies requiring a BAS procedure, the clock begins ticking at the moment of birth and access to immediate expert care is essential. At CHOP, we may recommend that these babies be delivered in our Garbose Family Special Delivery Unit, which is just steps away from our cardiac operative and catheterization facilities.
All children with transposition of the great arteries will require open heart surgery to treat the defect. Without surgical repair, the overwhelming majority of patients with TGA will not survive their first year. The surgery, known as the arterial switch operation, is typically performed within a few days of birth. Surgeons reconstruct the heart so that the aorta is attached to the left ventricle and the pulmonary artery is attached to the right ventricle.
After surgery your child will recover in our Tabas Cardiac Intensive Care Unit (CICU).
What is the follow-up care for TGA?
Through age 18
In the animation above, doctors describe the arterial switch operation. Children who have had surgical repair of TGA require life-long care by a cardiologist. Ongoing medication use is uncommon. More surgery may be required as the child grows.
Our pediatric cardiologists follow patients until they are young adults, coordinating care with the primary care physicians.
Into adulthood
We will help patients transition to an adult cardiologist.
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.
Until approximately 25 years ago, infants with transposition of the great arteries were managed by alternative surgical procedures, sometimes referred to as the "Senning" or "Mustard" operations. As a result, we don't yet know the truly long-term effects of the arterial switch operation beyond young adulthood. It is anticipated that the overwhelming majority of children born with TGA will go on to lead healthy, productive lives. Limitations to day-to-day activities, including sports, are rare.
Contact the Cardiac Center at The Children's Hospital of Philadelphia for a second opinion or for more information.
Reviewed by: Gil Wernovsky, MD
Date: October 2008
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