Generally, a patent foramen ovale doesn't cause complications. But, some studies have found the disorder is more common in individuals with certain conditions, such as unexplained stroke and migraine with aura. In most cases, there are other reasons for these conditions, and it's just a coincidence the person also has a patent foramen ovale. However, in some cases, blood clots in the heart may move through a patent foramen ovale, travel to the brain and cause a stroke. When this happens, it's often in people with conditions that increase the risk of blood clots, such as cancer.

The possible link between patent foramen ovale and stroke or migraine is controversial and research studies are ongoing.

In some cases a patent foramen ovale can cause a significant amount of blood to bypass the lungs, resulting in low blood oxygen levels (hypoxia). This usually happens when other conditions are present, such as congenital or valvular heart disease or pulmonary hypertension.

Nov. 01, 2012