A PFO is a type of hole in the heart that occurs in infancy. Treatment includes a catheter procedure or surgery to close the opening in 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. A PFO closure is a procedure that can help lower the risk of a stroke for some people. A patent foramen ovale occurs when a hole that is always present in a newborn's heart fails to close as it should once the lungs begin to function after birth. A patent foramen ovale (PFO) is a small hole between the two upper chambers of the heart, the right and the left atrium. Here's what you need to know. Treatment is a catheter procedure or surgery to close the opening in the heart. Most people with a patent foramen ovale don't need treatment.