Patent foramen ovale (PFO) is a hole between your heart's upper chambers. 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. In this procedure, the provider inserts a thin, flexible tube called a catheter into a blood vessel in the groin area. Patent foramen transcatheter repair is a procedure to fix this hole in the heart. Normally, the atrial septum separates the right and left atria. A patent foramen ovale (PFO) is a hole in the heart that didn't close the way it should after birth. The foramen ovale (feh-RAY-men oh-VAL-ee) is a normal opening between the upper two chambers (the right atrium and left atrium) of an unborn baby's heart. The foramen ovale (feh-RAY-men oh-VAL-ee) is a normal opening between the upper two chambers (the right atrium and left atrium) of an unborn baby's heart.