What is patent ductus arteriosus (PDA)?
Patent ductus arteriosus (PDA) is a heart condition caused by the failure of the ductus arteriosus to close. The ductus arteriosus normally is a temporary blood vessel connecting the main vessel leading to the lungs (pulmonary artery) to the main vessel of the body (aorta). If the vessel remains open after birth, it is called a patent ductus arteriosus or PDA. PDA occurs in about 10 percent of newborns.
Why does a baby have a ductus arteriosus?
Before birth, the fetus receives needed oxygen from the mother and the placenta. Since the fetus does not need to use his or her lungs, very little blood needs to go to them to help them grow. The ductus arteriosus allows most of the blood instead to bypass the lungs and go to the rest of the body.
At birth, the baby’s lungs take over and his or her body stops producing the chemicals that have kept the ductus arteriosus open. Under normal circumstances, the ductus arteriosus gradually narrows and eventually closes in the first few hours to days after birth.
If it doesn’t close, the baby has the defect known as patent (open) ductus arteriosus. This defect occurs especially in premature babies who have had respiratory distress syndrome (difficult breathing) due to immature lungs.
The cause of PDA is unknown. However, the condition is more common in premature babies as well as those born to mothers who had German measles (rubella) while they were pregnant.
What happens when the blood vessel stays open?
When the ductus arteriosus stays open, blood goes in the opposite direction than it would in the fetus: from the aorta to the lungs. This extra blood, along with the normal flow of blood from the heart to the lungs, can cause a build-up of blood in the baby’s lungs. If the PDA is large, this excess blood is too much for him or her to handle. As a result, fluid in the lungs increases, making it harder for the baby to breathe. Because PDA increases the amount of work for the heart, heart failure can result. The baby also has an increased risk of developing an infection in the blood vessel known as bacterial endocarditis.
How is PDA diagnosed?
Your doctor will look for the following symptoms if he or she suspects that your baby has PDA:
- He or she needs more oxygen or help breathing when he or she should be needing less.
- His or her breathing is more difficult and there is much more apnea (pauses in breathing).
- He or she is experiencing poor weight gain.
- The doctor or nurse hears a murmur (an abnormal noise created by blood flow, heard with a stethoscope).
- The baby’s heart rate increases and/or the pulse changes.
If the doctor suspects PDA, he or she will probably order an echocardiogram (an ultrasound of the heart) for your baby. During an echocardiogram, sound waves are used to produce a picture of the baby’s heart. This will help the doctor determine how much blood is flowing through the PDA. In rare cases, a baby with PDA might also have a heart malformation. The echocardiogram will detect this, too. This test is a painless procedure for the baby, being similar in principle to the ultrasound that many women have when they are pregnant.
How is PDA treated?
If the ductus arteriosus is very small or there is only a small amount of blood flowing through it, the doctor might simply wait to see if it closes by itself. If it doesn’t close after several months, there are treatment options.
If the baby is ill due to the PDA in the first few days of life, the baby might be placed on fluid restriction in order to close the ductus arteriosus. Another option is the drug ibuprofen, which is commonly used to treat PDA. Ibuprofen works by causing the ductus to narrow, permitting less blood to flow through it. Occasionally, another type of drug known as a diuretic will be given. Diuretics decrease the amount of fluid in the baby’s lungs while increasing the amount of urine that the baby makes.
If medicines do not work, or if the doctor does not think your baby should be given these drugs, the PDA might be tied off (ligated) surgically through an incision in the baby’s chest, under the left arm. If the baby is asymptomatic (showing no symptoms), closure of the PDA might be delayed until the infant is older, anywhere from 6 months to 3 years of age. At that time, it might be possible to close the PDA using an outpatient procedure in the cardiac cath lab, or surgery might be needed.
Children with PDA will spend some time in the NICU. However, recovery time is different for each child and the length of stay will vary. Often, infants who fed poorly prior to surgery have more energy after the recuperation period, and begin to eat better and gain weight faster.
When they go home, the pediatrician might prescribe pain medicines, such as acetaminophen or ibuprofen, to keep the child comfortable.
Can PDA return once it is closed?
Occasionally, the ductus closes for only hours or a few days in response to ibuprofen and a second course might be needed. However, once the PDA has gone away, it will not come back later in life.
- National Heart, Lung, and Blood Institute. What is Patent Ductus Arteriosus? www.nhlbi.nih.gov/. Accessed 11/18/2011.
- UpToDate. Clinical manifestations and diagnosis of patent ductus arteriosus. www.uptodate.com/. Accessed 11/18/2011.
- UpToDate. Management of patent ductus arteriosus. www.uptodate.com/. Accessed 11/18/2011.
© Copyright 1995-2011 The Cleveland Clinic Foundation. All rights reserved.
Can't find the health information you’re looking for?
This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on: 11/18/2011…#9859