Christopher Storm was a high school freshman running track when doctors found an abnormality in his heart. Part of the muscle was thicker than it should have been, making it harder for it to send blood to the rest of his body.
The condition, known as hypertrophic cardiomyopathy, is one of the most common causes of sudden cardiac death — when the heart abruptly stops beating.
Storm's disease was caught on an electrocardiogram (ECG), a test of the heart's electrical signals, done by volunteer doctors who visited his school.
"There was nothing — no lightheadedness, no reason for me to believe that anything was wrong," Storm, now 17, said almost two years after that test.
He believes it may have saved his life, but the idea of screening all young athletes for heart conditions is still controversial among medical experts.
Italy and many other European countries already screen teen and adult athletes before they play sports, and some researchers have also called for regular testing of U.S. kids and teens. But so far, data haven't definitively shown that screening could reliably weed out only the most at-risk kids and do so at an affordable price.
Based on Italian data, British researchers have calculated that close to 800 athletes like Storm would have to be kept out of sports, even given available treatment options, for every death prevented.
Not only that, but "you tell them that they're basically walking around with a ticking time bomb," said Dr. Anders Holst, from Copenhagen University Hospital in Denmark, adding that the vast majority will be scared unnecessarily.
Sudden cardiac death kills an estimated 100 to 1,000 children in the U.S. every year — an estimate that's so wide because reliable records of the deaths haven't been kept.
Because many young people with heart conditions never have symptoms, the diseases typically aren't caught until after a tragedy.
Most doctors acknowledge that screening isn't a perfect solution. Although an ECG can run as low as $10, costs add up when millions of kids are screened. Part of the reason is that some results generate false positives, suggesting abnormalities in hearts that are actually healthy. In one study, 7 percent of all ECG-screened athletes needed additional testing, which can add up to $2,000 per person.
Even if more invasive tests confirm underlying problems, it's usually impossible to tell which kids would have died as a result and which would never have had any trouble, researchers said.
The evidence supporting ECG screening comes largely from Italy, which implemented a program to screen all teens and adults in organized sports in 1982.
After 20 to 25 years of collecting data, Dr. Gaetano Thiene from the University of Padua Medical School and his colleagues say they've shown that screening and disqualifying some athletes saved lives.
In the Veneto region, the number of young athletes dying of sudden cardiac arrest fell from 1 in 28,000 each year to 1 in 250,000, according to a 2006 study published in the Journal of the American Medical Association.
But many doctors question whether the Italian results can be applied to the U.S. population.
For one, ECG screening is less accurate in non-Caucasians, according to Dr. Charles Berul, chief of cardiology at Children's National Medical Center in Washington, D.C.
The rate of sudden cardiac death in Americans is also lower, matching that of Italians who have already passed screening tests.
The early Italian figures "might have just been a blip to begin with," said Dr. Anne Dubin, a pediatric cardiologist at Stanford University and the Children's Heart Center in Palo Alto, Calif. "Or it could be that there are certain genetic rhythm problems that are inherent in Italy that we have here but not to the same extent."