By Jacqueline Stenson
September 04, 2001

Up to half of people who suffer from migraines have a common heart defect—a hole between their two upper chambers known as a patent foramen ovale (PFO). Patching the hole by snaking a catheter through the groin and into the heart to insert a tiny repair device brought noticeable relief to four out of five sufferers in a recent Swiss study involving 200 patients. The results, which support earlier findings, were reported at a European Society of Cardiology meeting.

Experts think PFOs may lead to migraines by allowing some substance, perhaps a tiny blood clot that impairs circulation or a chemical that irritates blood vessels, to reach your brain. Yet you may not know you have a PFO unless a doctor goes looking for it as a possible explanation for stroke. (PFOs are believed to be conduits for clots that travel to the brain and cause stroke.) All the study subjects were victims of stroke or had related symptoms. Because two-thirds had headaches (mostly migraines) as well, researchers wanted to find out whether patients' PFOs were linked to their headaches.

About 28 million Americans suffer from migraines. One-third may have a PFO that contributes to their pain, says study author Bernhard Meier, M.D., chairman of cardiology at the Swiss Cardiovascular Center in Bern, Switzerland. But experts say it's too soon to screen or treat all migraine patients for PFOs. Researchers at Swedish Medical Center's Cardiovascular Research Program in Seattle are hoping to get federal approval for a large clinical trial on the value of closing PFOs.