D-Transposition of the Great Arteries, Heart Institute at Johns Hopkins All Children's
Specialized care for children with the congenital heart defect d-TGA
D-Transposition of the great arteries (also called dextro-transposition of the great arteries or d-TGA) is a congenital heart defect in which the positions of the aorta and pulmonary artery are switched. Normally, the right ventricle pumps blood to the pulmonary artery and into the lungs, and the left ventricle pumps blood out of the aorta and into the rest of the body.
In d-TGA, this is reversed — the right ventricle pumps blood returning from the body back into the body, while the left ventricle pumps blood returning from the lungs back into the lungs. This results in abnormal circulation, which usually can be tolerated for only a short time.
Why choose Johns Hopkins All Children’s
Our heart surgeons provide expert care for children with d-TGA, with more than 30 years of experience in treating hundreds of children with this condition.
We work closely with other specialists in the Heart Institute to provide families with comprehensive, specialized care. Our fetal heart team specializes in diagnosing and managing heart conditions such as d-TGA before birth, and our cardiologists provide long-term care from diagnosis through adulthood.
How d-TGA is diagnosed
d-TGA may be detected during a fetal ultrasound and confirmed with a fetal echocardiogram.
After birth, d-TGA is usually diagnosed within the first hours of life. Babies with d-TGA appear blue (called “cyanosis”) after birth due to the decreased level of oxygen in the body’s bloodstream and may have rapid breathing. The decreased level of oxygen will be detected during the universal pulse oximetry screening, a test that estimates the amount of oxygen in a baby’s blood. All newborns receive this test before they can be discharged from the hospital following birth.
If the cyanosis is not corrected with oxygen, an echocardiogram is performed to look at the baby’s heart. Sometimes, a cardiac catheterization procedure may also be needed to improve the oxygen level in the body.
How d-TGA is treated
Immediate treatment involves establishing safe oxygenation and stable cardiac and pulmonary (lung) function. A continuous infusion of prostaglandins (a type of medication) is usually initiated. This medication will keep the ductus arteriosus open. The ductus arteriosus is an opening that connects the aorta and the pulmonary artery, that allows the fetus to receive oxygenated blood from the placenta before birth. It typically closes after birth. Keeping it open with medication allows the mixing of oxygen-rich blood with oxygen-poor blood before surgery in infants with d-TGA.
Babies with d-TGA will often undergo a cardiac catheterization procedure called “balloon atrial septostomy” after birth to temporarily improve the oxygen level in the body. A very small catheter (tube) is placed in a blood vessel in the groin or umbilical vessel and guided up to the heart. The catheter contains a small balloon that inflates to open a hole in the wall of the upper chambers of the heart. This allows oxygenated blood to mix with low-oxygen blood and improve oxygen levels in the body.
This procedure is temporary. All babies will need surgery after having this procedure. Surgery is usually performed within the first week of life. An arterial switch operation is typically performed where surgeons reconstruct the heart so that the aorta and coronary arteries are attached to the left ventricle and the pulmonary artery is attached to the right ventricle.
This allows low-oxygen blood to flow to the right ventricle and then to the lungs through the pulmonary artery. Oxygenated blood returns from the lungs to the left side of the heart, into the left ventricle and is pumped to the aorta to go to the rest of the body.
Babies with d-TGA also sometimes have an additional heart defect called a ventricular septal defect (VSD), in which there is a hole in the wall between the two lower chambers of the heart (the ventricles). Babies who have d-TGA with VSD are less likely to need the temporary balloon atrial septostomy. It may also affect the type of surgery they need because other valves in the heart may be narrowed. Your child’s care team will thoroughly explain the surgical treatment your child will need based on their individual condition.
Every baby with d-TGA will also have an additional heart defect called an atrial septal defect (ASD) — a hole between the two upper chambers of the heart (the atria) – to some degree. This is the same hole that is created with the “balloon atrial septostomy.” The ASD will also be repaired at the time of your child’s surgery.
What to expect after surgery for d-TGA
After your child’s surgery, they will be cared for in our cardiovascular intensive care unit.
The survival of children with d-TGA has improved significantly. Over 98% of infants undergo surgery in the newborn period and are discharged successfully. The long-term outcome of patients who have had surgical correction of d-TGA is excellent. They usually enjoy a near normal quality of life and very good exercise tolerance.
All patients require lifelong follow-up with a cardiologist to monitor for any significant changes. Your child will continue to be seen by their pediatric cardiologist and can continue to receive care from our experts as an adult in the Adult Congenital Heart Disease Program.
A very small number of patients may require some additional intervention or surgery for pulmonary artery, aortic valve or coronary related issues, but most patients will not need additional procedures.