Whats a patent foramen ovale?

Small heart opening: It is an opening in the wall between the upper chambers of the heart that allows blood from the placenta to get to where it needs to go during fetal life. All babies are born with this. It usually closes after birth, but 20% of all adults still have this. It is normal, though it has been associated with stroke, migraine headach, and decompression illness in scuba divers.

Hole in the heart: Patent foramen ovale is a opening between the atria (upper chambers ) of the heart. It allows blood to traverse the atria when a fetus. After birth the pfo closes to establish normal post natal circulation.