A patent foramen ovale (PFO) is a hole in the heart that should have closed after birth. Most people with a patent foramen ovale don't need treatment.A patent foramen ovale is a small, flaplike opening in the wall between the upper chambers of the heart. 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. The team at Arizona Heart Arrhythmia Associates can diagnose your structural heart defect and provide treatments to keep your heart working as it should. Treatment includes a catheter procedure or surgery to close the opening in the heart.