Transposition of the Great Arteries (TGA)
Transposition of the great arteries is a congenital birth defect in which the two arteries that carry blood from the heart are reversed, or transposed. This is a serious heart condition that can be fatal without treatment from experienced pediatric heart specialists like the team at University Hospitals Rainbow Babies & Children’s.
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What is Transposition of the Great Arteries?
In transposition of the great arteries, or TGA, the baby’s aorta is connected to the right ventricle instead of the left ventricle, and the pulmonary artery is connected to the left ventricle instead of the right. Because of this, oxygen-poor blood is sent to the body instead of the lungs, while the oxygen-rich blood is sent back to the lungs instead of to the body.
Unless there is some place where the oxygen-rich and oxygen-poor blood can mix together, the organs of the body will not get enough oxygen. This mixing can occur when babies have another heart defect such as a ventricular septal defect (VSD), which occurs in about 25 percent of children with TGA. Other defects that will allow some amount of blood mixing include atrial septal defect (ASD) and patent ductus arteriosus (PDA).
Without treatment, 90 percent of infants born with TGA will die within the first year of life, and over 50 percent will not survive their first month.
Signs and Symptoms of TGA
Transposition of the great arteries can sometimes be detected before a baby is born. If TGA is not diagnosed before birth, signs and symptoms will usually show up in the first hours of life, though sometimes it may take weeks or months to become apparent. Signs include:
- Cyanosis (bluish tint to skin, lips and nails)
- Low oxygen levels
- Rapid or labored breathing
- Difficulty feeding
Diagnosing Transposition of the Great Arteries
Transposition of the great arteries is sometimes detected though a fetal ultrasound while the baby is still in utero. If TGA is suspected but not confirmed with a regular fetal ultrasound, it can sometimes be diagnosed through a specialized ultrasound called a fetal echocardiogram (echo).
If a child has symptoms of a heart defect such as TGA after birth, he or she may be referred to one of UH Rainbow’s pediatric cardiologists for further examination and tests. These may include:
Chest X-ray
A chest X-ray shows the size and shape of the heart and lungs.
Electrocardiogram (ECG)
Records the heart’s electrical activity over a period of time.
Echocardiogram (echo)
Uses sound waves (ultrasound) to show blood flow patterns in the heart.
Cardiac catheterization
A noninvasive procedure that uses a catheter (a thin, flexible tube) inserted through a blood vessel in the leg or groin and guided into the heart to look at details of the heart’s structure.
Cardiac magnetic resonance imaging (MRI)
Creates a 3-D image of the heart.
Pulse oximetry
Measures blood oxygen levels through a non-invasive finger or toe monitor.
Recovering from Surgery
After surgery, your child will recover in the state-of-the-art pediatric cardiac intensive care unit (PCICU) where they will be cared for around the clock by a team of pediatric cardiac intensive care physicians, nurses and staff. As they recover, your child will transition from the PCICU to the pediatric cardiac stepdown unit, where they will receive continuity of care by specially trained staff. Before discharge, our cardiac nursing staff will work with families to set up follow-up appointments, educate them on how to care for their child once they return home, and ensure they have the necessary equipment and supplies.
Treating Transposition of the Great Arteries
Surgery is required for all infants with TGA in order to correct the defect and ensure that oxygen-rich blood is delivered to the body. Before surgery takes place, your child may need to be given oxygen or be put on a ventilator to help them breathe. They may also be given different medications to improve heart and lung function, as well as to help prevent the ductus arteriosus – an opening that is part of the fetal heart that typically closes after birth – from closing. This helps ensure that the body is still receiving oxygen-rich blood before surgery can take place.
Balloon atrial septostomy: This cardiac catheterization procedure may be done shortly after birth. It uses a balloon threaded through a catheter to create or enlarge an atrial septal defect, which allows for oxygen-rich blood to mix with oxygen-poor blood so that the body receives enough oxygen. After this procedure, the ductus arteriosus will be allowed to close since the blood is now mixing through the atrial septal defect. This procedure can help stabilize the baby in the short-term before surgery. The procedure can be done bedside or in the pediatric cardiac catheterization lab.
Arterial switch surgery: Surgery to correct TGA will typically take place within the first two weeks of life. During this open heart procedure, a pediatric cardiothoracic surgeon will cut the aorta and pulmonary artery and reconnect them to the proper ventricles. At the same time, the surgeon can also fix any other heart defects present, such as VSD.
All procedures are performed in our state-of-the-art hybrid catheterization and surgical suites. Our facility offers cutting-edge technology, including the most advanced imaging available worldwide and 3-D capabilities. This helps our surgeons better understand and visualize each patient’s unique anatomy while making complex repairs, leading to improved patient safety and outcomes.
Follow-up Care
The outlook for children who undergo surgical correction for transposition of the great arteries is generally good. After recovery, these children have improved heart function and quality of life, and usually do not need to limit physical activity as they get older. They will, however, need to have regular follow-up care with a congenital heart expert throughout their childhood and adult years. Their provider can perform tests to evaluate heart function and look for any potential problems. Some children may experience narrowing of the vessels where they were reattached during surgery. This may require additional cardiac catheterization procedures if the narrowing is severe.