Sam Peterman has won two sectional titles in high-school track races this season. She also collapses into her father's arms after nearly every race, because the 15-year-old—who's described as unassuming, quiet, and easy to smile—has a condition that screws up the relationship between her brain and her heart, the New York Times reports. "If he’s not there,” Sam says with a laugh about her dad, Dale Peterman, "the track hurts a lot." What's more, they didn't know for many months that her finish-line faintings were caused by NCS, or neurocardiogenic syncope. Even after she passed out for 40 minutes at a cross-country final in her home state of New York, and doctors had her wear a heart monitor for more than a month, no heart problem was found.
Then in January, Sam was tested by a Buffalo cardiologist and diagnosed with NCS. Still, Dale says, his daughter is allowed to hit the track running: "If we didn’t have the utmost medical clearance for her to run," he says, "she wouldn’t be running." Sam is also using her condition to draw attention to NCS, which "accounts for 3.5 percent of all emergency room visits" in the US, the New England Journal of Medicine reported in 2005. So what is it, exactly? In NCS sufferers, the brain misunderstands a rapidly pumping heart as a sign of high blood pressure, and works to lessen that pressure, which lowers the brain's blood flow and makes the person faint. But faint of heart, Sam isn't: "A lot of people will walk away," says Dale. "She chose not to walk away." (Read more medical condition stories.)