A patent foramen ovale is a small, flaplike opening in the wall between the upper chambers of the heart. The larger the hole, the more likely symptoms are.PFOs, on the other hand, are normal before birth but may fail to close after birth. Patent foramen ovale symptoms manifest as migraines, shortness of breath when getting up and standing, and a higher risk for certain kinds of strokes. These include sudden weakness or numbness, confusion, difficulty seeing out of an eye, or loss of coordination. Key points about patent foramen ovale. Most of the time, a PFO itself causes no symptoms. Sometimes symptoms do result from the complications of a PFO, such as stroke. A PFO may increase the risk of strokes because tiny blood clots elsewhere in the body can break loose and go to the heart via the blood. Dizziness, vertigo, swaying and loss of balance.