Pulmonary atresia (PA) is a complicated congenital (present at birth) defect that occurs due to abnormal development of the fetal heart during the first eight weeks of pregnancy.
The pulmonary valve is found between the right ventricle and the pulmonary artery. It has three leaflets that function like a one-way door, allowing blood to flow forward into the pulmonary artery, but not backward into the right ventricle.
With pulmonary atresia, problems with valve development prevent the leaflets from opening; therefore, blood cannot flow forward from the right ventricle to the lungs. Before birth, while the fetus is developing, this actually is not a threat to life, because the placenta provides oxygen for the baby and the lungs are not functional. Blood entering the right side of the fetal heart passes through an opening called the foramen ovale that allows oxygen-rich (red) blood to pass through to the left side of the heart and proceed to the body.
In some cases, there may be a second opening, this time in the ventricular wall, that allows blood in the right ventricle a way out. This opening is called a ventricular septal defect (VSD). If there is no VSD, the right ventricle receives little blood flow before birth and does not develop fully.
After birth, the placenta no longer provides oxygen for the newborn—the lungs must provide it. However, with no pulmonary valve opening present, blood must find another route to reach the lungs and receive oxygen.
The foramen ovale normally shuts at birth, but may stay open in this situation, allowing oxygen-poor (blue) blood to pass from the right atrium to the left atrium. From there, it goes to the left ventricle, out the aorta, to the body. This situation cannot support life, since oxygen-poor (blue) blood cannot meet the body's demands. Newborns also have a connection between the aorta and the pulmonary artery, called the ductus arteriosus, that allows some of the oxygen-poor (blue) blood to pass into the lungs. Unfortunately, this ductus arteriosus normally closes within a few hours or days after birth.
Because of the low amount of oxygen provided to the body, pulmonary atresia is a heart problem that is labeled "blue-baby syndrome."
The problem occurs as the heart is forming during the first eight weeks of fetal development.
Some congenital heart defects may have a genetic link, either occurring due to a defect in a gene, a chromosome abnormality, or environmental exposure, causing heart problems to occur more often in certain families. Most of the time, this heart defect occurs sporadically (by chance), with no clear reason for its development.
Symptoms will be noted shortly after birth. The obvious indication of PA is a newborn who becomes cyanotic (blue) in the transitional first day of life when the maternal source of oxygen (from the placenta) is removed. The degree of cyanosis is related to the presence of other defects that allow blood to mix, including a patent (open) ductus arteriosus.
The following are the most common symptoms of pulmonary atresia. However, each child may experience symptoms differently. Symptoms may include:
The symptoms of pulmonary atresia may resemble other medical conditions or heart problems. Always consult your child's physician for a diagnosis.
A pediatric cardiologist and/or a neonatologist may be involved in your child's care. A pediatric cardiologist specializes in the diagnosis and medical management of congenital heart defects, as well as heart problems that may develop later in childhood. A neonatologist specializes in illnesses affecting newborns, both premature and full-term.
Cyanosis is a major indication that there is a problem with your newborn. Your child's physician may have also heard a heart murmur during a physical examination. A heart murmur is simply a noise caused by the turbulence of blood flowing through the openings that allow the blood to mix.
Diagnostic testing for congenital heart disease varies by the child's age, clinical condition, and institutional preferences. Some tests that may be recommended include the following:
Specific treatment for pulmonary atresia will be determined by your child's physician based on:
Your child will most likely be admitted to the intensive care unit (ICU) or special care nursery once symptoms are noted. Initially, your child may be placed on oxygen, and possibly even on a ventilator, to assist his or her breathing. IV medications may be given to help the heart and lungs function more efficiently.
Other important aspects of initial treatment include the following:
These interventions will allow time for your baby to stabilize.
After surgery, infants will return to the ICU to be closely monitored during recovery.
While your child is in the ICU, special equipment will be used to help him or her recover, and may include the following:
Your child may need other equipment not mentioned here to provide support while in the ICU, or afterwards. The hospital staff will explain all of the necessary equipment to you.
Your child will be kept as comfortable as possible with several different medications; some of which relieve pain, and some of which relieve anxiety. The staff will also be asking for your input as to how best to soothe and comfort your child.
After discharge from the ICU, your child will recuperate on another hospital unit before going home. You will learn how to care for your child at home before your child is discharged. Your child may need to take medications for a while, and these will be explained to you. The staff will give you written instructions regarding medications, activity limitations, and follow-up appointments before your child is discharged.
Infants who spent a lot of time on a ventilator, or who were fairly ill while in the ICU, may have trouble feeding initially. These babies may have an oral aversion; they might equate something placed in the mouth, such as a pacifier or bottle, with a less pleasant sensation such as being on the ventilator. Some infants are just tired, and need to build their strength up before they will be able to learn to bottle-feed. Strategies used to help infants with nutrition include the following:
Pain medications, such as acetaminophen or ibuprofen, may be recommended to keep your child comfortable. Your child's physician will discuss pain control before your child is discharged from the hospital.
If any special treatments are to be given at home, the nursing staff will ensure that you are able to provide them, or a home health agency may assist you.
You may receive additional instructions from your child's physicians and the hospital staff.
The outlook varies from child to child. Follow-up care at a center offering pediatric congenital cardiac care should be carried out regularly. It is not unexpected for multiple re-operations to be performed to replace conduits or revise a palliation.
After each operation, your infant will need to be followed by a pediatric cardiologist who will make adjustments to medications, assist you with feeding problems, measure oxygen levels, and determine when it is time for the next operation.
There is significant risk for progressive development of complications such as heart failure, dysrhythmias, and protein-losing enteropathy (liver congestion).
Pregnancy and other non-cardiac surgeries pose major risks and require careful evaluation and discussion with a congenital cardiologist.
Regular follow-up care at a center offering pediatric or adult congenital cardiac care should continue throughout the individual's lifespan.
Consult your child's physician regarding the specific outlook for your child.
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Online Resources of Cardiovascular Disorders