Patent foramen ovale (PFO) is an interatrial communication at the level of oval fossa caused by the incomplete or missed fusion of the septum primum and septum secundum after birth. PFO has a ...

A patent foramen ovale or PFO is a defect in the wall between the two upper chambers of the heart ... If the flap does not seal, an individual can open, and blood can flow in either direction between ...