title: Patent foramen ovale.
abstract: Patent foramen ovale (PFO) is the most common congenital heart abnormality of fetal origin and is present in approximately ∼25% of the worldwide adult population. PFO is the consequence of failed closure of the foramen ovale, a normal structure that exists in the fetus to direct blood flow directly from the right to the left atrium, bypassing the pulmonary circulation. PFO has historically been associated with an increased risk of stroke, the mechanism of which has been attributed to the paradoxical embolism of venous thrombi that shunt through the PFO directly to the left atrium. However, several studies have failed to show an increased risk of stroke in asymptomatic patients with a PFO, and the risk of stroke recurrence is low in patients who have had a stroke that may be attributed to a PFO. With the advent of transoesophageal and transthoracic echocardiography, as well as transcranial Doppler, a PFO can be routinely detected in clinical practice. Medical treatment with either antiplatelet or anticoagulation therapy is recommended. At the current time, closure of the PFO by percutaneous interventional techniques does not appear to reduce the risk of stroke compared to conventional medical treatment, as shown by three large clinical trials. Considerable controversy remains regarding the optimal treatment strategy for patients with both cryptogenic stroke and PFO. This Primer discusses the epidemiology, mechanisms, pathophysiology, diagnosis, screening, management and effects on quality of life of PFO.
authors.affiliation: Department of Medicine, Columbia University, College of Physicians and Surgeons, 630 West 168th Street, New York 10032, USA.
authors.forename: Shunichi
authors.initials: S
authors.lastname: Homma
authors.affiliation: Department of Neurology, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania, USA.
authors.forename: Steven R
authors.initials: SR
authors.lastname: Messé
authors.affiliation: Department of Neurology, University of Miami School of Medicine, Miami, Florida, USA.
authors.forename: Tatjana
authors.initials: T
authors.lastname: Rundek
authors.affiliation: Department of Medicine, Columbia University, College of Physicians and Surgeons, 630 West 168th Street, New York 10032, USA.
authors.forename: Yee-Ping
authors.initials: YP
authors.lastname: Sun
authors.affiliation: Cardiovascular Center Frankfurt, Frankfurt, Germany.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Franke
authors.affiliation: Department of Medicine, Columbia University, College of Physicians and Surgeons, 630 West 168th Street, New York 10032, USA.
authors.forename: Karina
authors.initials: K
authors.lastname: Davidson
authors.affiliation: Cardiovascular Center Frankfurt, Frankfurt, Germany.
authors.forename: Horst
authors.initials: H
authors.lastname: Sievert
authors.affiliation: Department of Neurology, University of Miami School of Medicine, Miami, Florida, USA.
authors.forename: Ralph L
authors.initials: RL
authors.lastname: Sacco
authors.affiliation: Department of Medicine, Columbia University, College of Physicians and Surgeons, 630 West 168th Street, New York 10032, USA.
authors.forename: Marco R
authors.initials: MR
authors.lastname: Di Tullio
mesh_terms: D054087:Atrial Septum / Q000473:pathology / Q000503:physiopathology*; D006348:Cardiac Surgical Procedures / Q000295:instrumentation / Q000379:methods; D000013:Congenital Abnormalities / Q000453:epidemiology; D004452:Echocardiography / Q000379:methods; D019320:Embolism, Paradoxical / Q000453:epidemiology / Q000209:etiology / Q000503:physiopathology; D054092:Foramen Ovale, Patent / Q000150:complications* / Q000503:physiopathology* / Q000601:surgery; D006801:Humans; D015995:Prevalence; D012307:Risk Factors; D020521:Stroke / Q000453:epidemiology / Q000209:etiology