Screening for PDA often includes listening for a heart murmur with a stethoscope. However, doctors may not be able to hear premature babies’ heart murmurs, though they may suspect a problem if the baby has trouble breathing or feeding after being born. Some tests for PDA include a chest x-ray, in which the enlarged heart, which has expanded because of the larger-than-normal blood flow to the lungs, can be seen, as can changes to the lungs due to the extra blood flow; and an echocardiogram, which can show the pattern of blood flow through the PDA and determine how large the opening is and how much blood is passing through it. This is the most common test for diagnosing PDA.
Other tests include an electrocardiogram, or EKG, which can show if the heart is enlarged, and a cardiac catheterization, an invasive procedure that gives in-depth information about the heart’s structures. A cardiac catheterization can also be used to pass a device called a coil or PDA occlude into the heart to close the PDA.