Alaina Dufrene, 16, jumped at the chance to get into a Texas Heart Institute study because she worries she has some symptoms.
"Sometimes it gets very tight and I was just wanting to now what that meant," she said.
"Being as active as she is, we're concerned and I'm concerned by my family's history," Alaina's father, Kerby Dufrene, said.
The study includes an MRI scan of her heart.
"I thought, why not if it's free, and let's do it," Alaina's mother, Jessica Dufrene, said.
"We wanted to prevent sudden death," Texas Heart Institute President Dr. Jim Willerson said.
Dr. Willerson is conducting the study to learn which children are at risk of dying.
"It's about one-a-month in the United States drops dead on the playing fields. And it's sometimes football, sometimes basketball but a cheerleader dropped dead last year," he said.
To find out why, the Houston researchers plan to test 10,000 middle school and high school students, looking for some common but lethal heart malformations that can lead to sudden death.
The Texas Heart Institute researchers have conducted 3,400 MRIs on middle and high school students. And already they've found a worrisome trend. The number of serious heart problems they've found is five times higher than they'd expected.
Some needed only medicine; others needed surgery. But their abnormalities would never have been caught if not for this study.
"It's our hope, Dr. Angellini's and mine, that this would lead to a screening process in all schools ultimately that would be nearly fool proof and that would prevent this problem," Dr. Willerson said.
To save kids like sixth-grade volunteer Hannah Holliday.
"I think it's good because if kids just have a heart attack and fall over, they might find a way to stop it," Holliday said.