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patent ductus arteriosus





A heart problem that occurs soon after birth in some babies. In patent ductus arteriosus (PDA), there is an abnormal circulation of blood between two of the major arteries near the heart. Before birth, the two major arteries – the aorta and the pulmonary artery – are normally connected by a blood vessel called the ductus arteriosus, which is an essential part of the fetal circulation. After birth, the vessel is supposed to close within a few days as part of the normal changes occurring in the baby's circulation. In some babies, however, the ductus arteriosus remains open (patent). This opening allows blood to flow directly from the aorta into the pulmonary artery, which can put a strain on the heart and increase the blood pressure in the lung arteries.


patent ductus arteriosus
Figure A shows the normal anatomy and blood flow of the interior of the heart. Figure B shows a heart with a patent ductus arteriosus. The defect connects the aorta with the pulmonary artery, allowing oxygen-rich blood from the aorta to mix with oxygen-poor blood in the pulmonary artery.

A PDA is a type of congenital heart defect. A congenital heart defect is any type of heart problem that is present at birth.

If your baby has a PDA, but has an otherwise normal heart, the PDA may shrink and go away completely, or it may need to be treated to close it. But, if your baby is born with certain types of heart defects that decrease blood flow from the heart to the lungs or the body, medicine may be given to keep the ductus arteriosus open to maintain blood flow and oxygen levels until corrective surgery for the heart defect(s) can be performed.

About 3,000 infants are diagnosed with PDA each year in the United States. It is more common in premature infants (babies born too early) but does occur in full-term infants. Premature babies with PDA are more vulnerable to its effects. PDA is twice as common in girls as in boys.





What causes patent ductus arteriosus?

The cause of patent ductus arteriosus (PDA) is not known.

Genetics may play a role. A defect in one or more genes could prevent the ductus arteriosus from closing normally after birth.

PDA is more common in:
  • Premature infants (babies born too early)
  • Infants with genetic abnormalities such as Down's syndrome
  • Infants whose mother had German measles (rubella) during pregnancy

What are the signs and symptoms of patent ductus arteriosus?

A heart murmur may be the only sign that a baby has patent ductus arteriosus (PDA). A heart murmur is an extra or unusual sound heard during the heartbeat.

Some infants may develop signs or symptoms of volume overload on the heart and excess blood flow in the lungs. Signs and symptoms may include:
  • Fast breathing, working hard to breathe, or shortness of breath, or in the case of a premature infant, need for increased oxygen or ventilatory support
  • Poor feeding and poor weight gain
  • Tiring easily
  • Sweating with exertion (such as while feeding)

How is patent ductus arteriosus diagnosed?

In full-term infants, a patent ductus arteriosus (PDA) usually is first suspected when the baby's doctor hears a heart murmur during a regular checkup. If a PDA is large, the infant may also develop symptoms of volume overload and increased blood flow to the lungs. When a PDA is small, it may not be diagnosed until later in childhood. Once a PDA is suspected, a consultation with a pediatric cardiologist will be arranged. A pediatric cardiologist is a doctor who specializes in diagnosing and treating heart problems in children.

In premature babies (babies born too early) with PDA, the physical signs that are seen in full-term babies, such as heart murmur, may not be present. Doctors may suspect a PDA in premature babies who develop breathing difficulties soon after birth. Doctors use tests such as echocardiography to look for PDA in premature babies with breathing problems.


Tests

Two painless tests are used to diagnose a PDA.
  • Echocardiogram. This test, which is harmless and painless, uses sound waves to create a moving picture of your baby's heart. During an echocardiogram, reflected sound waves outline the heart's structure completely. The test allows the doctor to clearly see any problem with the way the heart is formed or the way it's working. An echocardiogram is the most important test available to your baby's cardiologist to both diagnose a heart problem and follow the problem over time. In babies with PDA, the echocardiogram shows how big the ductus is and how well the heart is responding to it. When medical treatments are used to try to close a ductus in premature babies, echocardiograms are used to see how well the treatment is working.

  • EKG (electrocardiogram). This test records the electrical activity in the heart. In the case of a PDA, it can show:
    • Enlargement of the heart chambers
    • Other subtle changes that can suggest the presence of a PDA

How is patent ductus arteriosus treated?

The goal of treatment is to close the patent ductus arteriosus (PDA) to prevent complications and reverse the effects of increased blood volume.

Small PDAs often close without treatment. For full-term infants, treatment is needed if the child's PDA:
  • Is large
  • Is causing the child to have health problems
  • Does not close on its own by the time the child is 12 years old
For premature infants (babies born too early), treatment is needed if the PDA is causing increased respiratory distress and heart problems.


Specific types of treatment

Treatments for PDA include:
  • Medicines
  • Catheter-based procedures
  • Surgery
Your child's doctor will discuss the treatment options and your family's preferences regarding treatment decisions.


Medicines

Medicines can be given to help close a PDA.
  • Indomethacin is a drug that helps close a PDA in premature infants. It does not usually work in full-term infants. It works by stimulating the PDA to constrict or tighten, closing the connection.
  • Ibuprofen is a medicine in the same family as indomethacin. It is also used frequently to close a PDA in premature infants.
If a PDA is small and the decision is made not to treat it right away, antibiotics are given in certain circumstances to prevent endocarditis.


Catheter-based procedures

Catheters are thin, flexible tubes used in a procedure called cardiac catheterization. Catheter-based procedures are often used to close PDAs in infants or children who are large enough to have the procedure. Your child's doctor may refer to the procedure as "transcatheter device closure." The procedure is sometimes done on small PDAs to prevent the risk of bacterial endocarditis.

During the procedure, your child will be sedated or given general anesthesia so he or she will sleep and not feel any discomfort. The doctor will place a catheter in a large blood vessel in the upper thigh (groin) and guide it to your child's heart.

A small metal coil or other blocking device is passed up through the catheter and placed in the ductus arteriosus to block blood flow through the vessel.

Catheter-based procedures:
  • Do not require the child's chest to be opened
  • Let the child recover quickly
Closing a PDA using a catheter is often done on an outpatient basis. You will most likely be able to take your child home the same day the procedure is done.

Complications of catheter-based procedures are rare and short term. They can include bleeding, infection, and movement of the blocking device from where it was placed.


Surgery

Surgery for PDA may be performed when:
  • A premature or full-term infant develops health problems from the PDA and is too small to have a catheter-based procedure
  • A PDA is not successfully closed by a catheter-based procedure
  • Surgery is planned for treatment of related congenital heart defects
Surgery often is not performed until after 6 months of age in infants who do not have health problems from the PDA. Doctors sometime perform surgery on small PDAs to prevent the risk of bacterial endocarditis.

The operation is done under general anesthesia so that your child will sleep and not feel any pain. The surgeon will:
  • Make a small cut between your child's ribs to reach the PDA
  • Close the PDA with stitches or clips
Complications of the surgery are rare and usually short term. They can include hoarseness, a paralyzed diaphragm, infection, bleeding, or fluid buildup around the lungs.

After surgery. After surgery, your child will spend a few days in the hospital. Most children go home 2 days after surgery. While in the hospital, your child will be given medicines to reduce pain or anxiety. The doctors and nurses at the hospital will teach you how to care for your child at home. They will talk to you about:
  • Limits on activity for your child while he or she recovers
  • Followup appointments with your child's doctors
  • How to give your child medicines at home, if needed
When your child goes home after surgery, you can expect that he or she will feel fairly comfortable, although there may be some pain temporarily.

Your child should begin to eat better and gain weight quickly. Within a few weeks, your child should be fully recovered and able to participate in normal activities.

Long-term complications from surgical treatment are rare. They can include narrowing of the aorta, incomplete closure of the ductus arteriosus, and reopening of the ductus arteriosus.


Living with patent ductus arteriosus

Most children are healthy and live normal lives after treatment for a patent ductus arteriosus (PDA).

If your child was not born prematurely (too early), he or she is expected to have normal activity levels, appetite, and growth after PDA treatment, as long as there are no other congenital heart defects.

If your child was born prematurely, the outlook after PDA treatment depends primarily on other factors, such as:
  • How early he or she was born
  • Whether he or she has other illnesses or conditions, such as other congenital heart defects

Medical care needs

Children with PDAs have an increased risk of bacterial endocarditis. To prevent this infection, your doctor will give your child antibiotics before dental work and certain procedures.

It's important to take good care of your child's teeth. He or she should have regular dental care to prevent decay and help reduce the chance of infection.

Once the PDA is closed, your child will not need antibiotics before dental work or surgical procedures. If the PDA is closed surgically or by catheter and remains completely closed, antibiotics will not be needed after 6 months.


Related categories

   • HEART TOPICS
   • HEALTH AND DISEASE

Source: U.S. National Heart, Lung and Blood Institute