Patent Ductus Arteriosus (PDA)

What is a PDA?

We are all born with a blood vessel called a ‘ductus arteriosus’ – don’t be freaked out by the Latin! It’s just a long word that describes the connection between the two major blood vessels in the body - the aorta, which carries red (high oxygen) blood to the body and the pulmonary artery, which carries blue (low oxygen) blood to the lungs.

» Click here to take an animated tour of the normal heart

Normally this connection closes within a few hours after birth, so that there is no flow between the aorta and the pulmonary artery.

The term PDA is shorthand for Patent Ductus Arteriosus. Translating this into plain English:

  • Patent = Open
  • Ductus Arteriosus = the blood vessel between the aorta and the pulmonary artery

Therefore, PDA means an OPEN BLOOD VESSEL between the aorta and the pulmonary artery.

The problem with this blood vessel remaining open is that blood continues to flow from the aorta into the lungs. Small PDAs are usually not a big deal because this blood flow is limited. However, if it’s a big PDA, lots of blood can flow into the lungs. This can lead to high blood pressure in the lungs, also known as pulmonary hypertension.

Is this common?

It’s not very common in adults, but we still see quite a few people with PDAs.

If I have a PDA, what do I need to know?

The symptoms of a PDA depend on its size and how much blood flows to the lungs. Small PDAs usually cause no symptoms and treatment is rarely needed.

Larger PDAs can cause weakening of the heart muscle and pulmonary hypertension. You should tell your doctor about the following symptoms:

Will I need treatment as I get older?

Most small PDAs don’t cause any symptoms. Still, it’s a good idea to check in with your cardiologist to make sure that the heart is OK, and to prevent complications.

Larger PDAs are rare in adults since most of these are corrected during childhood. Treatment options in adults with a PDA include:

  • Surgery: More than 95% of PDAs can be closed by open-heart surgery
  • Device closure: Patients may also have the PDA closed using a closure device, or coil. This is less invasive than surgery and involves a cardiac catheter study. A small coil is inserted in the connection between the aorta and pulmonary artery, with the aim of plugging the PDA.

You can discuss which option is best for you after speaking with your cardiologist.

Some patients with open PDAs get high pressures in the lung and low oxygen levels. This is called Eisenmenger Syndrome. If you have Eisenmenger Syndrome, you definitely need to be seen by cardiologists or respirologists in an Adult CHD centre. Treatment can include:

  • Pills to control the heart rate
  • Pills to help keep the heart strong
  • Pills to improve blood flow to the lungs
  • Blood thinners
  • Iron replacement
  • Phlebotomy ( = a fancy word for removal of blood)