How Is Patent Ductus Arteriosus Diagnosed?

In full-term infants, a patent ductus arteriosus (PDA) usually is first suspected when the baby's doctor hears a heart murmur during a regular checkup. If a PDA is large, the infant may also develop symptoms of volume overload and increased blood flow to the lungs. When a PDA is small, it may not be diagnosed until later in childhood. Once a PDA is suspected, a consultation with a pediatric cardiologist will be arranged. A pediatric cardiologist is a doctor who specializes in diagnosing and treating heart problems in children.

In premature babies (babies born too early) with PDA, the physical signs that are seen in full-term babies, such as heart murmur, may not be present. Doctors may suspect a PDA in premature babies who develop breathing difficulties soon after birth. Doctors use tests such as echocardiography to look for PDA in premature babies with breathing problems.

Tests

Two painless tests are used to diagnose a PDA.

• Echocardiogram. This test, which is harmless and painless, uses sound waves to create a moving picture of your baby's heart. During an echocardiogram, reflected sound waves outline the heart's structure completely. The test allows the doctor to clearly see any problem with the way the heart is formed or the way it's working. An echocardiogram is the most important test available to your baby's cardiologist to both diagnose a heart problem and follow the problem over time. In babies with PDA, the echocardiogram shows how big the ductus is and how well the heart is responding to it. When medical treatments are used to try to close a ductus in premature babies, echocardiograms are used to see how well the treatment is working.
• EKG (electrocardiogram). This test records the electrical activity in the heart. In the case of a PDA, it can show:
  • Enlargement of the heart chambers
  • Other subtle changes that can suggest the presence of a PDA