The ductus arteriosus (DA) is a normal blood vessel that connects two major arteries — the aorta and the pulmonary artery — that carry blood away from the heart in a developing fetus. The DA diverts blood away from the lungs, sending it directly to the body.
The lungs are not used while a fetus is in the amniotic fluid because the baby gets oxygen directly from the mother's placenta. When a newborn breathes and begins to use the lungs, the DA is no longer needed and usually closes during the first 2 days after birth.
But when the DA fails to close, a condition called patent (meaning "open") ductus arteriosus (PDA) results, in which oxygen-rich blood from the aorta is allowed to mix with oxygen-poor blood in the pulmonary artery. As a result, too much blood flows into the lungs, which puts a strain on the heart and increases blood pressure in the pulmonary arteries.
The cause of PDA is not known, but genetics might play a role. PDA is more common in premature babies and affects twice as many girls as boys. It's also common among babies with neonatal respiratory distress syndrome, babies with genetic disorders (such as Down syndrome), and babies whose mothers had German measles (rubella) during pregnancy.
In the vast majority of babies with a PDA but an otherwise normal heart, the PDA will shrink and go away on its own in the first few days of life. Some PDAs that don't close then will close on their own by the time the child is a year old.
In premature infants, the PDA is more likely to stay open, particularly if the baby has lung disease. When this happens, treatment to close the PDA might be considered.
In infants born with additional heart defects that decrease blood flow from the heart to the lungs or decrease the flow of oxygen-rich blood to the body, the PDA could actually be beneficial and the doctor might prescribe medicine to keep the ductus arteriosus open.
Symptoms and Tests
Babies with a large PDA might experience symptoms such as:
- a bounding (strong and forceful) pulse
- fast breathing
- poor feeding habits
- shortness of breath
- sweating while feeding
- tiring very easily
- poor growth
If a PDA is suspected, the doctor will use a stethoscope to listen for a heart murmur, which is often heard in babies with PDAs. Follow-up tests might include:
- a chest X-ray
- an EKG, a test that measures the heart's electrical activity and can show if the heart is enlarged
- an echocardiogram, a test that uses sound waves to diagnose heart problems. These waves bounce off parts of the heart, creating a picture of the heart that is shown on a monitor. In babies with PDA, an echo shows how big the opening is and how well the heart is handling it.
The three treatment options for PDA are medication, catheter-based procedures, and surgery. A doctor will close a PDA if the size of the opening is large enough that the lungs could become overloaded with blood, a condition that can lead to an enlarged heart.
A PDA also might be closed to reduce the risk of developing a heart infection known as endocarditis, which affects the tissue lining the heart and blood vessels. Endocarditis is serious and requires treatment with intravenous (IV) antibiotics.
Reviewed by: Gina Baffa, MD
Date reviewed: February 2012
|National Heart, Lung, and Blood Institute (NHLBI) The NHLBI provides the public with educational resources relating to the treatment of heart, blood vessel, lung, and blood diseases as well as sleep disorders.|
|Congenital Heart Information Network The Congenital Heart Information Network's goal is to provide information and resources to families of children with congenital and acquired heart disease, adults with congenital heart defects, and the professionals who work with them.|
|American Heart Association This group is dedicated to providing education and information on fighting heart disease and stroke. Contact the American Heart Association at: American Heart Association|
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|National Institutes of Health (NIH) NIH is an Agency under the U.S. Department of Health and Human Services, and offers health information and scientific resources.|
|American Academy of Pediatrics (AAP) The AAP is committed to the health and well-being of infants, adolescents, and young adults. The website offers news articles and tips on health for families.|
|Coarctation of the Aorta Coarctation of the aorta is a treatable congenital defect in which a child's aorta is narrowed at some point.|
|Ventricular Septal Defect Ventricular septal defect (VSD) - also known as a "hole in the heart" - is a congenital heart defect. Fortunately, most VSDs are diagnosed and treated successfully.|
|Heart Murmurs and Your Child A heart murmur diagnosis is extremely common. Most murmurs are not a cause for concern and do not affect a child's health.|
|If Your Child Has a Heart Defect Congenital heart defects are relatively common, affecting almost 1 in every 100 newborns in the United States.|
|Atrial Septal Defect Atrial septal defect (ASD) - also known as a "hole in the heart" - is a type of congenital heart disease. Fortunately, most ASDs are diagnosed and treated successfully.|
|Heart and Circulatory System The heart and circulatory system are our body's lifeline, delivering blood to the body's tissues. Brush up on your ticker with this body basics article.|
|Congenital Heart Defects Congenital heart defects involve abnormal or incomplete development of the heart. Learn about the different types of congenital heart defects.|
|Arrhythmias Arrhythmias are abnormal heart rhythms usually caused by an electrical "short circuit" in the heart. This can lead to a variety of symptoms including fatigue, dizziness, and chest pain.|
Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor.
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