If your infant or child has been diagnosed with tricuspid atresia (TA), an understanding of the condition will help you to cope with this very rare congenital (present at birth) heart defect.
- In tricuspid atresia, the tricuspid valve—which is normally located between the right atrium and the right ventricle—is abnormal and does not open.
- The failure of the tricuspid valve to develop results in a small (or missing) right ventricle that can’t adequately pump blood to the lungs.
- While very serious, tricuspid atresia is treatable surgically, and surgical advances have greatly improved children’s outcomes.
Comparison with normal heart
In a normal heart, oxygen-poor (blue) blood returns to the right atrium from the body, travels to the right ventricle, then is pumped through the pulmonary artery into the lungs, where it receives oxygen. And oxygen-rich (red) blood returns to the left atrium from the lungs, passes into the left ventricle, then is pumped through the aorta out to the body.
click on images to enlarge
In tricuspid atresia, improper development of the tricuspid valve prevents oxygen-poor (blue) blood from passing from the right atrium to the right ventricle and on to the lungs as it should. As a result, the right ventricle is underdeveloped (hypoplastic).
Like many congenital heart conditions, tricuspid atresia isn’t a single defect, but rather a cluster of associated defects in various combinations and with varying degrees of severity:
- In addition to a missing tricuspid valve and underdeveloped right ventricle, most TA defects are accompanied by secondary defects called atrial septal defect (ASD) and ventricular septal defect (VSD), which are essentially holes in the tissue walls (septa) that normally separate the right and left atria (ASD) and the right and left ventricles (VSD).
- These ASD and VSD holes are actually useful in this condition, since they allow oxygen-poor (blue) blood and oxygen-rich (red) blood to mix, providing at least some oxygen supply to circulate. But the heart often has to work extra hard to carry enough oxygen through the body.
- A third defect is called the patent ductus arteriosus (PDA). In this condition, a blood vessel (ductus arteriosus) which connects the two great arteries (aorta and pulmonary artery), and which usually closes soon after birth, fails to do so. The PDA remains open (patent), allowing blood to pass from the aorta to the pulmonary artery.
- This opening allows some oxygen-rich blood to circulate to the lungs to pick up oxygen. However, it can strain the heart, as well as increasing blood pressure in the lung arteries.
- A narrowing or blockage of the passageway to the lungs (pulmonary valve stenosis) may also be present with tricuspid atresia. And occasionally, when the VSD is very large, there is also transposition of the great arteries (TGA), in which the normal positions of the aorta and pulmonary artery are reversed.
The Boston Children's Hospital approach
The experienced surgeons in Boston Children’s Cardiac Surgery Department understand how distressing a diagnosis of a tricuspid atresia can be for parents. You can have peace of mind knowing that our surgeons treat some of the most complex pediatric heart conditions in the world, with overall success rates approaching 98 percent—among the highest in the nation among large pediatric cardiac centers. For tricuspid atresia, our 30-day hospital survival rate for the past five years for each of the three necessary operations has been higher than 98 percent.
At Boston Children’s, we provide families with a wealth of information, resources, programs and support—before, during and after your child’s treatment. With our compassionate, family-centered approach to expert treatment and care, you and your child are in the best possible hands.
Tricuspid atresia: Reviewed by Michael Freed, MD, and Thomas Kulik, MD
© Boston Children's Hospital, 2010