Associations of patent foramen ovale

Associations of patent foramen ovale (PFO)

Associations of patent foramen ovale: Patent foramen ovale (PFO) is a small defect in the inter atrial septum in the region of the fossa ovalis, between the layers contributed by the septum primum and septum secundum. Due to the specific direction of the valvular opening, blood can shunt from the right atrium to left atrium, especially during a Valsalva maneuver.

Common associations of a PFO are:

1. Eustachian valve
2. Chiari network
3. Atrial septal aneurysm

Eustachian valve is at the opening of the inferior vena cava into the right atrium and tends to direct the inferior vena caval blood across the patent foramen ovale. It is a remnant of the embryonic right valve of the sinus venosus.

Chiari network, also a remnant of the right valve of the sinus venosus, is a network of filamentous structures sometimes seen in the right atrium.

Atrial septal aneurysm is located in the fossa ovalis region where the septum primum overlies the septum secundum.

Right to left shunting across the patent foramen ovale can cause paradoxical embolism and stroke. It has been implicated in the pathogenesis of cryptogenic stroke. Though there was a significant correlation between septal excursion distance and infarct volume, in a study, 12 patients with atrial septal aneurysms did not have the largest strokes [1].

Reference

1. Andre Akhondi, Rubine Gevorgyan, Chi-Hong Tseng, Leo Slavin, Catherine Dao, David S Liebeskind, Jonathan M Tobis. The Association of Patent Foramen Ovale Morphology and Stroke Size in Patients With Paradoxical Embolism. Circ Cardiovasc Interv. 2010 Oct;3(5):506-10.