Patent foramen ovale (PFO)

Patent foramen ovale (PFO) is a congenital heart defect characterized by the persistence of a small flap-like opening between the right and left atria (upper chambers) of the heart. Normally present during fetal development, PFO allows blood to bypass the fetal lungs, which are nonfunctional before birth. After birth, the foramen ovale typically closes. In about 25–34% of adults, it remains open but usually causes no symptoms[1][2][3][5][6]. Most individuals with PFO are asymptomatic, but in some, the defect can permit abnormal passage of blood clots from the venous to arterial circulation (paradoxical embolism), potentially leading to stroke, transient ischemic attack (TIA), or other sequelae. PFO has also been linked to certain types of migraine (with aura) and decompression illness in divers. Diagnosis is usually made by specialized echocardiography. The mainstay of treatment for at-risk patients is closure of the opening using a catheter-based device; routine closure for all patients is not recommended and requires careful clinical evaluation[1][2][3][5][6].

Other names

Patent foramen ovalePFOForamen ovale persistens

Not applicable (structure, not protein or signaling molecule); surgical or percutaneous device closure is the main intervention when indicated