What is patent ductus arteriosus (PDA)?

Before a baby is born, their blood flow is different than after they are born. While a baby is in the womb, the placenta is responsible for oxygenating the blood, and most of the blood bypasses the lungs, which are still developing.

This is possible because of an extra blood vessel between the pulmonary artery and the aorta. This blood vessel is called the ductus arteriosus (DA). The ductus arteriosus allows blood from the right side of the heart to bypass the lungs and flow to the aorta, which is the artery that carries oxygenated blood to the body without going through the lungs. 

After the baby is born and begins to breathe, pressures in the lung normalize.  There is no longer a placenta, and the ductus arteriosus begins to close, usually within a few days after birth.

In babies and children with a patent ductus arteriosus (PDA), the ductus arteriosus doesn't close. Sometimes, this open passageway is wide (a large PDA) and sometimes it is narrow (a small PDA). A large PDA can cause more blood flow to the lungs than needed. This can lead to problems with the lungs and heart.

PDA is most common in premature infants but can also occur in babies and children who are not premature. If the PDA persists and does not close, these babies and children may need an intervention to close the PDA. 

Signs and symptoms of patent ductus arteriosus

Symptoms vary depending on the size of the PDA. Children with a tiny or small PDA usually have no symptoms. Symptoms in children with a larger PDA may include:

• Breathing difficulties soon after birth (especially in premature babies)
• Heart murmur, or an abnormal sound heard through a stethoscope, which is the blood flowing through the ductus arteriosus 
• Rapid breathing
• Difficulty feeding and poor growth
• A strong pulse, (sometimes called a “bounding” pulse)
• Lung infections (pneumonia)

Testing and diagnosis of PDA

Neonatologists — doctors who care for premature babies — work with the Cardiac Center team at Children's Hospital of Philadelphia (CHOP) to diagnose and treat PDA in newborns and premature babies. Older infants and children with PDAs are typically referred to the Cardiac Center with a heart murmur. 

To diagnose patent ductus arteriosus, your care team may use:

• Echocardiogram (also called echo or ultrasound), which are sound waves that create an image of the heart
• Electrocardiogram (ECG), which is a record of the electrical activity of the heart
• Chest X-ray

Some infants with PDA have other heart defects and will require additional tests, including  cardiac catheterization  and cardiac MRI (magnetic resonance imaging).

Treatment for patent ductus arteriosus

Small PDAs often close on their own, so some children may not require any treatment. If the PDA is large, your child’s cardiologist may recommend closing the PDA.

In premature babies with too much blood flow to the lungs, medications can be used to help close the PDA. If the PDA does not close or narrow significantly in response to the medicine, an interventional cardiac catheterization procedure or surgery may be necessary.

During a cardiac catheterization procedure, an interventional cardiologist will insert a thin tube (catheter) through a vein or artery in the leg and then guide it in and around the heart. A tiny device is then inserted to block blood flow to the PDA. This procedure can be done for premature babies and older children. 

Most older infants and children go home the same day after this procedure, though some may spend one night in CHOP’s dedicated post-catheterization recovery unit before returning home. After a few days of rest, most older children can return to normal activity. Premature babies recover in the NICU (Neonatal Intensive Care Unit).

In complex cases of PDA, surgery may be required. CHOP’s cardiothoracic surgeons use stitches or clips to close the PDA, typically through an incision in between the ribs on the left side of the chest.