New advice about a common heart variation: Patent foramen ovale (PFO)

About 25% of people have a patent foramen ovale or PFO, a flaplike opening between the heart’s upper chambers. Most people never know they have it, because a PFO doesn’t cause any signs or symptoms. For the most part, the condition is harmless. But it may allow small amounts of blood to leak across the heart from the right atrium to the left atrium without getting filtered by the lungs. PFOs may be responsible for up to 10% of strokes among people younger than 60. Guidelines now recommend a procedure to close a PFO for young stroke survivors with no other obvious risk factors for stroke.