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.A patent foramen ovale is a small, flaplike opening in the wall between the upper chambers of the heart. Most people with PFO go their whole lives without any symptoms. In fact, PFO is usually discovered only when patients undergo tests for other heart conditions. A surgical closure of the PFO is done for patients < 60 yr with unclear cause for stroke despite extensive workup to reduce recurrence of another stroke. This hole may let blood flow between the atria. PFO often has no symptoms. A PFO does not generally cause problems. In most people, a PFO creates no symptoms and requires no treatment.