Pulmonary atresia is a very rare type of congenital heart defect in which the pulmonic valve is permanently closed or completely absent from the heart. This valve is located between the right ventricle and the pulmonary artery. It is responsible for opening and closing at precise moments to allow blood to flow from the heart through the pulmonary artery and to the lungs, where it is infused with oxygen. When the pulmonic valve completely malfunctions, oxygen-poor blood cannot reach the lungs and, therefore, cannot be oxygenated.

The symptoms of pulmonary atresia typically appear shortly after birth. The most obvious sign is a baby who appears cyanotic (known as blue baby), indicating the lack of sufficient oxygen in the blood. The degree of cyanosis will vary depending on the presence of other conditions, such as a patent ductus arteriosus - another heart defect that allows oxygen-poor and oxygen-rich blood to mix. Other symptoms may include breathing difficulties, lethargy and pale skin color.

During a physical examination of a patient with suspected pulmonary atresia, a cardiologist may detect a heart murmur through a stethoscope. To help diagnose the condition, a number of tests may be ordered including a chest x-ray, electrocardiogram (EKG) and cardiac magnetic resonance imaging (MRI). In addition, cardiac catheterization may be used to evaluate this and other heart defects that may exist in the patient.

Treatment for pulmonary atresia is determined by the age and overall health of the patient, as well as the severity of the defect and tolerance for treatment. Early treatment for pulmonary atresia may include a drug that prevents the patent ductus arteriosus from closing. Surgery is typically needed to treat pulmonary atresia. The type of corrective surgery that will be performed depends greatly on what other heart defects are present.

Without treatment, a patient’s chance of long-term survival is poor because the body cannot get enough oxygen-rich blood. Fortunately, the treatments available offer patients a greater chance of a healthy and active life.

Pulmonary atresia is a type of congenital heart defect in which the pulmonic valve is permanently closed or completely absent from the heart. The pulmonic valve is located between the lower-right chamber of the heart (right ventricle) and the pulmonary artery. The valve normally opens and closes at precise moments to allow the smooth passage of oxygen-poor blood from the right ventricle into the pulmonary artery and to the lungs. The complete closure of the pulmonic valve means that oxygen-poor blood cannot reach the lungs in order to get fresh oxygen.

Because blood is prevented from getting to the lungs for fresh oxygen, the baby’s body does not get enough oxygen-rich blood. As a result, the baby is born with a bluish tint (cyanosis) to the skin, lips, fingernails and other parts of the body. This condition is often called blue baby.

Although the pulmonic valve is closed, the baby can get enough oxygen immediately after birth because of certain structures unique to a newborn's heart. These are temporary openings that connect vital areas of the heart during prenatal development. These structures are called the foramen ovale, connecting the right and left atria, and ductus arteriosus, connecting the aorta to the pulmonary artery.

In a normal baby, both of these structures close within the first few days or weeks of birth. For a baby with pulmonary atresia, the natural closure of the structures is very dangerous because it closes off the only connection between the lungs and the circulatory system. For this reason, keeping these structures open is important to allow blood with oxygen to circulate throughout the baby’s body.

 The first and most noticeable outward sign of pulmonary atresia is a bluish tint (cyanosis) to the baby’s skin, lips, fingernails and other parts of the body, a condition often called blue baby. Other signs that may be present include the following:

• Shortness of breath (dyspnea) and/or rapid breathing
  
  
• Difficulty eating or sucking
  
  
• Pale skin that may be cool or clammy
  
  
• Poor weight gain
  
  
• Slow growth or other physical retardation

The diagnosis of pulmonary atresia usually begins with a physician taking a complete medical history and giving a physical examination. During the physical examination, a heart murmur may be detected by the physician through a stethoscope. If a heart defect is detected, the infant will likely be referred to a cardiologist or pediatric cardiologist (doctor who specializes in heart conditions in children). To help diagnose the condition, the cardiologist may order several tests, including:

• Electrocardiogram (EKG). This noninvasive test measures the heart’s electrical activity and displays it on a screen for the physician to view. It can help determine if the heart is functioning properly. This test can be administered while the baby is still in the womb.
  
  
• Echocardiogram. A noninvasive test that uses ultrasound to produce an image of the heart’s structure and function. This will help the physician image the pulmonic valve and determine if the right ventricle is undeveloped. This test can be administered while the baby is still in the mother's womb.
  
  
• Chest x-ray. A noninvasive test that can help the physician determine if any of the heart’s chambers are abnormally enlarged. This test can only be conducted after the baby is born.
  
  
• Cardiac magnetic resonance imaging (MRI). A noninvasive test that uses magnetic fields to create three-dimensional images of the heart. It can help determine the blood flow and functioning of the heart in motion.

Surgery is generally needed to treat pulmonary atresia. If corrective surgery cannot be done immediately, babies may be given medications called prostaglandins to temporarily keep the ductus arteriosus open. Palliative surgery (surgery that relieves the symptoms, rather than cures the condition) is generally needed to treat pulmonary atresia, and may include a Blalock-Taussig shunt between the aorta and the pulmonary artery. This performs the same function as an open ductus arteriosus, and allows the ductus arteriosus to close naturally. 

The type of corrective surgery that will be performed depends greatly on what other heart defects are present. If both the pulmonary artery and the right side of the baby’s heart have developed normally, then a surgeon may perform a valvotomy. Also known as a valvulotomy, a valvotomy is a type of open-heart surgery in which the surgeon cuts into the pulmonic valve to open it.

Alternatively, the surgeon may perform a heart valve replacement to replace the baby’s closed valve with a valve from a human donor. The surgeon will also close any minor heart defects that may be present, such as an atrial septal defect or patent foramen ovale. After surgery, the baby’s circulation should be quite normal. However, patients may need to undergo another heart valve replacement surgery within the next 10 years or so as the new valve slowly wears out. In other cases, the surgeon may perform a Fontan operation.

The outlook for children who have undergone treatment for pulmonary atresia varies from child to child. Treatment offers children with heart defects the best chances for a healthy, productive life.

Children with pulmonary atresia need to be monitored throughout their life by a cardiologist to check their heart function. These patients will sometimes need to take antibiotics before dental, medical or surgical procedures. Antibiotics will reduce their risk of developing a potentially fatal bacterial infection (endocarditis), which affects the lining of the valves or the heart itself. In addition, good oral hygiene and regular dental check-ups lowers the risk of endocarditis.

As with most congenital heart defects, there are no known strategies for preventing pulmonary atresia. Women who are pregnant are advised to undergo regular prenatal check-ups, including regular ultrasounds. If serious birth defects are detected early, parents and their physicians can prepare for the birth of the child and plan any necessary treatment. Additionally, pregnant women are advised to avoid exposure to conditions or agents that may increase the likelihood of having congenital defects in the fetus, such as exposure to radiation, infections and certain medications. This is particularly important during the first eight weeks of fetal development when the heart is being formed. However, in most cases, heart defects occur by chance with no definitive cause.

Preparing questions in advance can help patients to have more meaningful discussions with their physicians regarding their conditions. Parents and patients may wish to ask their doctor the following questions related to pulmonary atresia:

1. Why do you suspect that my child has pulmonary atresia?
   
   
2. IS pulmonary atresia a threat to my child's life?
   
   
3. What will happen to my child if the problem is not corrected?
   
   
4. If my child has pulmonary atresia, is he/she likely to have any other type of heart conditions?
   
   
5. What tests will be used to diagnose any heart defects in my child?
   
   
6. What type of treatment is available for pulmonary atresia?
   
   
7. If surgery is necessary, what type of procedure will be performed?
   
   
8. What are the risks associated with this surgery?
   
   
9. What is the typical recovery with this type of surgery?
   
   
10. How will you know if the surgery has been successful?
    
    
11. What is the outlook for my child?
    
    
12. How will my child’s heart be monitored through life?
    
    
13. What are the chances that my child will need additional surgeries later in life?
    
    
14. What precautions should we take after the defect has been corrected?
    
    
15. What is your experience in treating patients with this heart condition?