Does a Patent Foramen Ovale Increase Stroke Risk?
One of my recent entries described a possible relationship between strokes and a patent foramen ovale. The foramen ovale is an opening in the fetus between the right and left sides of the heart that usually closes shortly after birth. The foramen ovale remains open, or patent, in about a quarter of healthy people. Doctors have suggested that blood clots normally filtered out by the lungs can pass through the opening and be carried by the bloodstream to the brain, where they may cause a stroke by lodging in an artery. The topic is particularly timely now with the news that the small stroke suffered in December by Israel’s prime minister, Ariel Sharon, was attributed to a patent foramen ovale. Sharon was scheduled to have this defect corrected surgically before he suffered a second, major hemorrhagic stroke. In December a group from the Mayo Clinic concluded that a patent foramen ovale is not an independent risk factor for stroke. They had identified a patent foramen ovale in 140 of 585
