Patent foramen ovale
What is a patent foramen ovale (PFO)?
A Patent Foramen Ovale (PFO) is a small tunnel located in the septum (muscular wall) that separates the receiving chamber of the heart into the left and right sides. This tunnel is important during fetal circulation as it allows blood to take a short-cut through the heart bypassing the non-breathing lungs.
Often the tunnel closes soon after birth but otherwise it can works like a flap valve, only opening during certain conditions when there are pressure changes in the chest and heart chambers. These changes may occur when people strain while having a bowel movement, cough, sneeze or laugh.
If the pressure is great enough, blood may travel from the right atrium to the left atrium. In the rare event that there happens to be clot or particles in the blood traveling to the right side of the heart, they could potentially cross the PFO, enter the left atrium, and travel out of the heart and to the brain (causing a stroke) or into a coronary artery (causing a heart attack).
Should that occur then the patient can be treated medically with blood thinning medication or the PFO tunnel can be closed non-surgically using implantable umbrella-type devices (watchman's procedure).