A test called an echocardiogram is used to diagnose a PFO. The test uses sound waves to create pictures of the beating heart.A patent foramen ovale, or PFO, is a special type of hole between the upper chambers of the heart. Patent foramen ovale (PFO) is a hole between your heart's upper chambers. Patent foramen transcatheter repair is a procedure to fix this hole in the heart. Normally, the atrial septum separates the right and left atria. In the past, open heart surgery or a lifetime of dependence on blood thinning medication were the only known treatments for PFO and ASD. The hole is a small flaplike opening between the upper heart chambers. The upper chambers of the heart are called the atria. PFOs, on the other hand, are normal before birth but may fail to close after birth.