A PFO has no symptoms that a person would see, feel or notice. In fact, a PFO can be diagnosed only through a specific type of medical test known as an echocardiogram, which is a non-invasive test that uses sound to create a moving picture of the heart. This test may also be called a Doppler, bubble test or bubble study, heart ultrasound or ‘echo.’

Because there is no way to diagnose a PFO except through the use of an echocardiogram, many PFOs are diagnosed when a doctor is conducting tests for a different problem, such as a previous stroke, or a heart condition such as atrial fibrillation (Afib).

There are three types of echocardiography: transthoracic echocardiogram (TTE), transesophageal echocardiogram (TEE) and intracardiac echocardiogram (ICE). A TTE takes images within the body from the skin’s surface, without devices entering the body. For TEE, images are taken from within the esophagus (food pipe). ICE involves taking images by introducing a catheter into the femoral vein at the groin and delivering the tip of the catheter into the right atrium of the heart. TEE and ICE can provide more detailed images than traditional echocardiography, but they are more invasive methods. A page of information about echocardiograms, what they can diagnose and how they work, is available here.