Patent Ductus Arteriosus (PDA)

High-Risk Newborns - Patent Ductus Arteriosus (PDA)

Anatomy of the heart, normal
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What is PDA?

PDA is a heart problem that is usually noted in the first few weeks or months after birth. It is characterized by a connection between the aorta and the pulmonary artery which allows oxygen-rich (red) blood that should go to the body to recirculate through the lungs.

All babies are born with this connection between the aorta and the pulmonary artery. While your baby was developing in the uterus, it was not necessary for blood to circulate through the lungs because oxygen was provided through the placenta. During pregnancy, a connection was necessary to allow oxygen-rich (red) blood to bypass your baby's lungs and proceed into the body. This normal connection that all babies have is called a ductus arteriosus.

At birth, the placenta is removed when the umbilical cord is cut. Your baby's lungs must now provide oxygen to his or her body. As your baby takes the first breath, the blood vessels in the lungs open up, and blood begins to flow through to pick up oxygen. At this point, the ductus arteriosus is not needed to bypass the lungs. Under normal circumstances, within the first few days or weeks after birth, the ductus arteriosus closes and blood no longer passes through it. Most babies have a closed ductus arteriosus by 72 hours after birth.

Illustration of the anatomy of a heart with a patent ductus arteriosus
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In some babies, however, the ductus arteriosus remains open (patent) and the condition now becomes known as patent ductus arteriosus (PDA). The opening between the aorta and the pulmonary artery allows oxygen-rich (red) blood to pass back through the blood vessels in the lungs.

PDA accounts for 5 to 10 percent of congenital heart disease. Patent ductus arteriosus occurs twice as often in girls as in boys.

What causes PDA?

Almost all children have a PDA present at birth. In some children, the PDA does not close, and remains open. Although exact reasons why this happens in some patients and not in others are not known, the most common association for a PDA is prematurity.

PDA can also occur in combination with other heart defects.

Why is PDA a concern?

When the ductus arteriosus stays open, oxygen-rich (red) blood passes from the aorta to the pulmonary artery, mixing with the oxygen-poor (blue) blood already flowing to the lungs. The blood vessels in the lungs have to handle a larger amount of blood than normal. How well the lung vessels are able to adapt to the extra blood flow depends on how big the PDA is and how much blood is able to pass through it from the aorta.

Extra blood causes higher pressure in the blood vessels in the lungs. The larger the volume of blood that goes to the lungs at high pressure, the more the lungs have to cope with this extra blood at high pressure.

Children will have increased difficulty breathing because of this extra blood flow to the lungs at high pressure. They may remain on the ventilator for a longer period of time, especially if premature in the first place, which often requires support from the ventilator. The support from the ventilator also may be high, due to this extra blood flow to the lungs.

Rarely, some older children may have too much blood going to the lungs that the lungs get damaged. This is uncommon, however, since most children will have been treated for their PDA before the lungs get damaged.

Often, the PDA may be "silent," that is, causing no symptoms. This is especially true in older patients (beyond the first few months of life).

What are the symptoms of PDA?

The size of the connection between the aorta and the pulmonary artery will affect the type of symptoms noted, the severity of symptoms, and the age at which they first occur. The larger the opening, the greater the amount of blood that passes through that overloads the lungs.

A child with a small patent ductus arteriosus might not have any symptoms, and your child's doctor may have only noted the defect by hearing a heart murmur. Other infants with a larger PDA may exhibit different symptoms. The following are the most common symptoms of PDA. However, each child may experience symptoms differently. Symptoms may include:

The symptoms of a PDA may resemble other medical conditions or heart problems. Always consult your child's doctor for a diagnosis.

How is PDA diagnosed?

Your child's doctor may have heard a heart murmur during a physical examination, and referred your child to a pediatric cardiologist for a diagnosis. A heart murmur is simply a noise caused by the turbulence of blood flowing through the opening from the left side of the heart to the right.

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. The cardiologist will perform a physical examination, listening to the heart and lungs, and make other observations that help in the diagnosis. The location within the chest where the murmur is heard best, as well as the loudness and quality of the murmur (harsh, blowing, etc.) will give the cardiologist an initial idea of which heart problem your child may have. 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:

Treatment for PDA

Specific treatment for PDA will be determined by your child's doctor based on:

A small patent ductus arteriosus may close spontaneously as your child grows. A PDA that causes symptoms will require medical management, and possibly even surgical repair. Your child's cardiologist will check periodically to see whether the PDA is closing on its own. If a PDA does not close on its own, it will be repaired to prevent lung problems that will develop from long-time exposure to extra blood flow. Treatment may include:

Postprocedure care for your child:

Care for your child at home following PDA repair

Most infants and older children feel fairly comfortable when they go home. Pain medications, such as acetaminophen or ibuprofen, may be recommended to keep your child comfortable. Your child's doctor will discuss pain control before your child is discharged from the hospital.

Often, infants who fed poorly prior to surgery have more energy after the recuperation period, and begin to eat better and gain weight faster.

After surgery, older children usually have a fair tolerance for activity. Your child will usually be allowed to play, while avoiding blows to the chest that might cause injury to the incision or breastbone. Within a few weeks, your child should be fully recovered and able to participate in normal activity.

You will receive additional instructions from your child's doctors and the hospital staff.

Long-term outlook after PDA surgical repair

In premature infants, the outlook after PDA surgical repair depends on the following:

In children born full-term, most that had a patent ductus arteriosus diagnosed and repaired early will live healthy lives after recovering from the hospitalization. Activity levels, appetite, and growth should return to normal. Your child's cardiologist may recommend that antibiotics be given to prevent bacterial endocarditis for a specific time period after discharge from the hospital if the coil or occluder device was used.

In children whose PDA was diagnosed late and/or never repaired, the outlook is uncertain. There is a risk for pulmonary hypertension (increased blood pressure in the blood vessels of the lungs). These individuals should receive follow-up care at a center that specializes in congenital heart disease.

Consult your child's doctor regarding the specific outlook for your child.

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