Patent foramen ovale overview


 * Associate Editors-In-Chief: Priyamvada Singh, M.B.B.S. [mailto:psingh@perfuse.org]; Assistant Editor-In-Chief: Kristin Feeney, B.S. [mailto:kfeeney@perfuse.org]

Overview
A patent foramen ovale is a communication between the right and left atrium. Despite the communication between the two atrium, it is not considered an atrial septal defect as the septal tissue is not missing.

Epidemiology and Demographics
The incidence of Patent foramen ovale has been found to be approximately 30% in different studies. . The incidence decreases with increasing age, but the size increases with age. There is no difference in the incidence associated with gender.

Natural History, Complications and Prognosis
A Patent foramen ovale is often asymptomatic and may be an incidental finding on echocardiography. A PFO may be identified following the development of complications such as stroke, migraine, the platypnea orthodeoxia syndrome or decompression sickness.

Decompression illness is associated with a 5 to 13 fold increased incidence of a patent foramen ovale. The risk increases with an increase in defect size. Device closure can be considered in divers with unexplained decompression illness, especially those who wish to continue diving. The number of ischemic brain lesions were twice as common among patients with a patent foramen ovale than in those without it.

Causes
The exact causes for patent foramen ovale is still not clear. However, it has been found to occur with increased frequencies in families and might have some genetic component to it.

Symptoms and sign
Most individuals with patent foramen ovale are asymptomatic although some may present with rare symptoms like migraines, stroke, decompression illness and platypnoea orthodeoxia syndrome.

Echocardiography
Transthoracic echocardiography (TTE), transesophageal echocardiography (TEE), and transcranial Doppler (TCD) are the commonly used diagnostic tools for patent foramen ovale. Transesophageal echocardiography is more sensitive in visualizing the interatrial septum, than transthoracic echocardiography and is the imaging modality of choice,. Transthoracic echocardiography (TTE) with contrast at rest, with cough, and after valsalva maneuver is generally considered the most definitive diagnostic test for PFO.

Medical therapy
The medical therapy for the patients with patent foramen ovale is controversial. Medical therapy with antiplatelet therapy (aspirin) or anticoagulant therapy (warfarin) could be considered in patients with recurrent strokes after index episode of cryptogenic stroke and unresponsive migraines. However, the relative effectiveness of aspirin or warfarin in these patients has not been proved.

Percutaneous closure
There is lack of consensus regarding the effectiveness of percutaneous closure of patent foramen ovale. There are insufficient evidences to recommend device closure for a first stroke. PFO closure may be considered for recurrent cryptogenic stroke and high-risk patent foramen ovale (PFO) (atrial septal aneurysm).