Patent foramen ovale (PFO) is a common anatomical finding in a quarter of the general population and
under certain conditions may shunt clot, deoxygenated blood or gas bubbles right-to-left across the atrial septum
to cause cryptogenic stroke, platypnoea orthodeoxia or decompression illness respectively. PFO has also been
linked to migraine with aura. Treatment by percutaneous closure as a day case is technically feasible and has been
aided by the recent development of intracardiac and 3D transoesophageal imaging, as well as improvements in
device technology. The results from several large randomised controlled trials designed to assess superiority of
PFO closure above medical therapy alone for cryptogenic stroke are eagerly awaited.
