Pulmonary atresia

Pulmonary atresia (uh-TREE-zhuh) is a heart defect present at birth (congenital) that's usually diagnosed soon after birth. In pulmonary atresia, the valve that lets blood out of the heart to go to the lungs (pulmonary valve) doesn't form correctly.

Instead of opening and closing to allow blood to travel from the heart to the lungs, a solid sheet of tissue forms. So, blood can't travel its usual route to pick up oxygen from the lungs. Instead, some blood travels to the lungs through other natural passages within the heart and its arteries.

These passages are necessary when a baby is developing in the womb, and they typically close soon after birth. Babies with pulmonary atresia typically have a bluish cast to their skin because they aren't getting enough oxygen.

Pulmonary atresia is a life-threatening situation. Procedures to correct a baby's heart condition and medications to help a baby's heart work more effectively are the first steps to treat pulmonary atresia.

Symptoms

If a baby is born with pulmonary atresia, symptoms will be noticeable soon after birth. Signs and symptoms might include:

• Blue- or gray-toned skin (cyanosis)
• Fast breathing or shortness of breath
• Easily tiring or being fatigued
• Feeding problems

When to see a doctor

A baby with pulmonary atresia will most likely be diagnosed soon after birth. However, if your baby has symptoms of pulmonary atresia after you've returned home, seek emergency medical attention.

Causes

There's no known cause of pulmonary atresia. To understand how pulmonary atresia occurs, it may be helpful to know how the heart works.

How the heart works

The heart is divided into four hollow chambers, two on the right and two on the left. In performing its basic job — pumping blood throughout the body — the heart uses its left and right sides for different tasks.

The right side of the heart moves blood to the lungs through vessels called pulmonary arteries. In the lungs, blood picks up oxygen then returns to the heart's left side through the pulmonary veins. The left side of the heart then pumps the blood through the aorta and out to the rest of the body to supply the body with oxygen.

Blood moves through the heart in one direction through valves that open and close as the heart beats. The valve that allows blood out of the heart and into the lungs to pick up oxygen is called the pulmonary valve.

In pulmonary atresia, the pulmonary valve doesn't develop properly, preventing it from opening. Blood can't flow from the right ventricle to the lungs.

Before birth, the irregular valve isn't life-threatening, because the placenta provides oxygen for the baby instead of the lungs. Blood entering the right side of the baby's heart passes through a hole (foramen ovale) between the top chambers of the baby's heart, so the oxygen-rich blood can be pumped out to the rest of the baby's body through the aorta.

After birth, the lungs are supposed to provide oxygen to the body. In pulmonary atresia, without a working pulmonary valve, blood must find another route to reach the baby's lungs. The foramen ovale usually shuts soon after birth, but it may stay open in pulmonary atresia.

Newborn babies also have a temporary connection (ductus arteriosus) between the aorta and the pulmonary artery. This passage allows some of the oxygen-poor blood to travel to the lungs, where it can pick up oxygen to supply the baby's body. The ductus arteriosus typically closes soon after birth, but it can be kept open with medications.

Sometimes, there may be a second hole in the tissue that separates the main pumping chambers of the baby's heart. This hole is a ventricular septal defect (VSD).

The VSD allows a pathway for blood to pass through the right ventricle into the left ventricle. Children with pulmonary atresia and a VSD often have additional problems with the lungs and the arteries that bring blood to the lungs.

If there's no VSD, the right ventricle receives little blood flow before birth and often doesn't develop fully. This is a condition called pulmonary atresia with intact ventricular septum (PA/IVS).

Risk factors

The exact cause of a congenital heart defect, such as pulmonary atresia, is usually unknown. However, several things may increase a baby's risk of a congenital heart defect, including:

• A parent who has a congenital heart defect
• Obesity in the mother before pregnancy
• Smoking before or during pregnancy
• A mother who has poorly controlled diabetes
• Use of some types of medications during pregnancy, such as certain acne drugs and blood pressure medications

Complications

Without treatment, pulmonary atresia usually leads to death. Regular health checkups are needed after pulmonary atresia surgery to carefully monitor for complications.

Potential complications of pulmonary atresia and other structural heart problems include:

• Bacterial infection of the inner lining of the heart and valves (infectious endocarditis)
• Irregular heart rhythms (arrhythmias)
• Heart failure

Prevention

Because the exact cause of pulmonary atresia is unknown, it may not be possible to prevent it. However, some things can be done before or during pregnancy to help reduce a baby's overall risk of congenital heart defects, such as:

• Control chronic medical conditions. If you have diabetes, keeping your blood sugar in check can reduce the risk of heart defects. If you have other chronic conditions, such as high blood pressure or epilepsy, that require the use of medications, discuss the risks and benefits of these drugs with your health care provider.
• Don't smoke. Smoking cigarettes during pregnancy may increase the risk of heart defects in a baby.
• Maintain a healthy weight. Obesity increases the risk of having a baby with a congenital heart defect.
• Get a German measles (rubella) vaccine. German measles during pregnancy may affect a baby's heart development. Being vaccinated before becoming pregnant likely eliminates this risk. However, no link has been shown between rubella and the development of pulmonary atresia.

Diagnosis

Tests to diagnose pulmonary atresia may include:

• Chest X-ray. A chest X-ray shows the size and shape of the heart and lungs. This can help the baby's health care provider see the extent of your baby's pulmonary atresia.
• Electrocardiogram (ECG or EKG). This quick and painless test measures the electrical activity of the heart. Sticky patches (electrodes) are placed on the chest and sometimes the arms and legs. Wires connect the electrodes to a computer, which displays the test results. This test detects irregular heart rhythms (arrhythmias) and may show heart muscle stress.
• Echocardiogram. In this test, sound waves are used to create pictures of the heart in motion. An echocardiogram is usually the main test used to diagnose pulmonary atresia. An echocardiogram done during pregnancy (fetal echocardiogram) can help diagnose this condition before birth.
• Cardiac catheterization. A health care provider threads a thin tube (catheter) through a blood vessel in the arm or groin to an artery in the heart and injects dye through the catheter. This makes the heart arteries show up more clearly on an X-ray.

Treatment

A baby will need urgent medical attention once pulmonary atresia symptoms develop. The choice of surgeries or procedures depends on the severity of the child's condition.

Medications

Medication may be given through an IV to help prevent the closure of the natural connection (ductus arteriosus) between the pulmonary artery and the aorta. This is not a permanent treatment for pulmonary atresia, but it gives health care providers more time to determine what type of surgery or procedure might be best for the child.

Surgery or other procedures

Sometimes, pulmonary atresia repairs can be done using a long, thin tube (catheter) inserted into a large vein in a baby's groin and threaded up to the heart. Catheter-based procedures for pulmonary atresia include:

• Balloon atrial septostomy. A balloon is used to enlarge the natural hole (foramen ovale) in the wall between the upper two chambers of the heart. This hole usually closes shortly after birth. Making the hole larger increases the amount of blood available to travel to the lungs.
• Stent placement. A health care provider may place a rigid tube (stent) in the natural connection between the aorta and pulmonary artery (ductus arteriosus). This opening also usually closes soon after birth. Keeping it open allows blood to travel to the lungs.

Babies with pulmonary atresia often require a series of heart surgeries over time. The type of heart surgery needed will depend on the size of the child's right ventricle and pulmonary artery. Some examples include:

• Shunting. Creating a bypass (shunt) from the main blood vessel leading out of the heart (aorta) to the pulmonary arteries allows for adequate blood flow to the lungs. However, babies usually outgrow this shunt within a few months.
• Glenn procedure. In this surgery, one of the large veins that returns blood to the heart is connected directly to the pulmonary artery instead. Another large vein continues to provide blood to the right side of the heart, which pumps it through the surgically repaired pulmonary valve. This can help the right ventricle grow larger.
• Fontan procedure. If the right ventricle remains too small to be useful, surgeons may use this procedure to create a pathway that allows most, if not all, of the blood coming to the heart to flow directly into the pulmonary artery.
• Heart transplant. In some cases, the heart is too damaged to repair and a heart transplant may be necessary.

Lifestyle and home remedies

Here are some tips for caring for your child after coming home from the hospital:

• Keep regular follow-up appointments with your child's health care provider. Your child will likely need regular appointments with a doctor trained in congenital heart disease. These appointments need to continue even after your child is an adult. Ask how frequently your child needs to be seen.

• Help your child stay active. Encourage as much play and activity as your child is able to tolerate, with plenty of time for rest and nap time. Staying active helps a child's heart stay fit.

  As your child grows, talk with a heart doctor (cardiologist) about which activities are best for your child. If some are off-limits, such as competitive sports, encourage your child in other pursuits rather than focusing on what can't be done.

• Keep up with routine well-child care. Get recommended vaccines.
• Preventive antibiotics. Your child's cardiologist may recommend that your child take antibiotics before certain dental and other procedures to prevent bacteria from entering the bloodstream and infecting the inner lining of the heart (infective endocarditis).
• Practice good oral hygiene. Brushing and flossing teeth and getting regular dental checkups can help prevent infection.

Coping and support

Talking with other parents who've been through a similar situation may bring comfort and encouragement. Ask your child's health care provider about local support groups.

Preparing for an appointment

It's most likely that your child would be diagnosed with pulmonary atresia soon after birth while still in the hospital. If your child is diagnosed with pulmonary atresia, you'll be referred to a heart specialist (cardiologist) for ongoing care.

Because appointments can be brief, and because there's often a lot to discuss, it's a good idea to be prepared for your appointment. Here's some information to help you get ready for your appointment, and what to expect from your health care provider.

What you can do

• Be aware of any pre-appointment restrictions. At the time you make the appointment, be sure to ask if there's anything you need to do in advance, such as fill out forms or restrict your child's diet. For some imaging tests, for example, your child may need to avoid food or drinks for a period of time beforehand.
• Write down any symptoms your child has, including any that may seem unrelated to pulmonary atresia. Try to recall when they began. Be specific, such as days, weeks, months.
• Write down key personal information, including any family history of congenital heart defects, pulmonary hypertension, or other heart or lung diseases. Also note any major stresses or recent life changes.
• Make a list of all medications that your child is taking, and the doses. Include vitamins and supplements. Also, tell the health care provider about any medications taken during pregnancy.
• Take a family member or friend along, if possible. Sometimes it can be difficult to remember all the information received during an appointment. Someone who goes with you may remember something that you missed or forgot.
• Write down questions to ask your child's health care provider.

For pulmonary atresia, some basic questions to ask your child's health care provider include:

• What are other possible causes for my child's symptoms or condition?
• What tests will my child need?
• What's the best treatment?
• Are there any activities my child should avoid?
• How often should my child be screened for changes?
• What are the alternatives to the primary approach that you're suggesting?
• Could you recommend a specialist who has experience treating congenital heart defects?
• Is there a generic alternative to the medicine you're prescribing?
• Are there brochures or other printed material that I can have? What websites do you recommend?

Don't hesitate to ask other questions.

What to expect from your child's doctor

Your child's health care provider might ask:

• Has anyone else in your family been diagnosed with pulmonary atresia or another congenital heart defect?
• Does the child always have symptoms or do the symptoms come and go?
• How severe are the child's symptoms?
• What, if anything, seems to improve the symptoms?
• What, if anything, appears to worsen the symptoms?

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