This hole may let blood flow between the atria. PFO often has no symptoms.A patent foramen ovale is a small, flaplike opening in the wall between the upper chambers of the heart. Some adults with PFOs also suffer from migraine headaches. Patent foramen ovale symptoms manifest as migraines, shortness of breath when getting up and standing, and a higher risk for certain kinds of strokes. The foramen ovale is a hole in the wall between the left and right atria of every human fetus. This hole allows blood to bypass the fetal lungs. What are symptoms of a patent foramen ovale? Most of the time, a PFO itself causes no symptoms. Most of the time, PFO itself causes no symptoms.