The sudden deaths of two high school athletes within days have many parents and support groups fighting for heart screenings of all athletes. But many experts say such blanket screenings would not be effective in preventing these kinds of deaths.
Matthew Hammerdorfer, a 17-year-old from Larimer County, Colo., took a powerful hit to the chest during a rugby game Saturday and collapsed on the field. He was airlifted to a hospital, where he died.
An autopsy performed Sunday found the cause of Hammerdorfer's death was cardiomegaly and biventricular hypertrophy, which means an enlarged heart and enlarged ventricles. The Larimer County deputy coroner Kari Jones, however, noted that the family knew about Hammerdorfer's genetic heart condition. Hammerdorfer had previously undergone three heart surgeries because of his heart condition, according to Jones.
Despite the worrisome idea that participating in a vigorous sport like rugby contributed to Hammerdorfer's death, experts said his parents' previous knowledge of his heart condition precludes the idea that mandatory screening could have prevented it.
"It becomes an issue of how was he followed and whether he and his family made a well-informed decision to [allow him to] stay engaged in competitive sports like rugby," said Dr. Michael Ackerman, director of the Mayo Clinic Windland Smith Rice sudden death genomics laboratory at the Mayo Clinic in Rochester, Minn. "If they knew of the risks and made this choice, then tragic, yes, but not relevant to screening."
Hammerdorfer's death came days after Michigan high school basketball player Wes Leonard collapsed and died after scoring the winning shot for his team, leaving his coach, team and the community devastated.
Both young men's deaths were caused by sudden cardiac death, and experts said it occurs far too often in young athletes.
It is estimated that one in every 350 children may have dangerous underlying heart conditions. But it comes with warnings -- nearly half of those who experienced sudden cardiac death had experienced warning signs.
"Athletes are at higher risk than the general population because they exercise more," said Dr. Jonathan Drezner at the University of Washington.
One major indicator of an underlying heart condition is sudden fainting during exercise, according to the Sudden Arrhythmia Death Syndromes Foundation. A family history of congenital heart defects also puts one at a potentially higher risk and in need of screening.
Teenagers and young people dying of heart failure is more common than one might think: An average of 40 young athletes die from heart disease in the United States a year. That's approximately one death every nine days.
Many experts said recognition of early warnings signs is crucial in preventing sudden death. But advocacy groups want additional screening measures, believing broader screening could save lives.
Parent Heart Watch is one such group working to encourage awareness and preventive measures that would avert such deaths. It believes young athletes should get early and mandatory electrocardiograph, or ECG, screening, which looks at the activity of the heart over time.
Other groups also want schools and teams to have heart defibrillators at games, and have coaches and parents learn CPR.
The European Society of Cardiology and International Olympic Committee endorsed standardized screenings that have been credited with lowering the sudden cardiac death rate in Italy.
But previous U.S. studies suggest no added benefit from such screening methods, and U.S. medical groups don't recommend them. Although ECG screening may not have made a difference for Hammerdorfer, since he'd been previously diagnosed with a congenital heart problem, it is not known whether such testing could potentially benefit athletes like Leonard, who had no clues.
One argument against standardized electrocardiograph screenings for all athletes is that they cost too much. Some believe the money could be better spent putting automatic external defibrillators at every sporting event.
Dr. Douglas Zipes, editor of Heart Rhythm, told ABC News that to cover the $1,200 cost of a defibrillator, "you could get 120 fathers to kick in 12 bucks each."
There's also the danger of false positives -- suggesting that athletes are at risk when they are not -- with such blanket screeing. And ECGs are unlikely to detect certain types of heart problems in some, said Dr. Brian Olshansky, a professor of medicine at the University of Iowa Hospitals.
For every 200,000 people screened, it is estimated that only one would yield a true positive for a heart abnormality. "The overall value of an EKG screening program remains highly problematic," said Olshansky.
Ackerman acknowledged that for some families who have lost a loved one to sudden cardiac death, a false positive could be seen "an acceptable nuisance." But he said the rate would be too high for it to become an acceptable way of determining who's at risk.
"Overdiagnosis is not trivial, and it can be just as tragic as missing it in somebody," Ackerman said, adding that it could lead to the sidelining of too many athletes.
While blanket screening may not be an adequate method to detect congenital heart problems that contribute to sudden death, Ackerman said there are steps families would take right away.
"Know your personal story, know your family history and advocate for a community rapid AED," an automated external defibrillator, said Ackerman.
ABC News' Clayton Sandell and Kevin Dolak contributed to this report.