(CNN) -- There were 35 black and orange balloons at Wes Leonard's funeral in Fenville, Michigan, on Tuesday, to represent the number on his high school basketball jersey. Even athletes from other schools who had competed against him were moved to tears.
Leonard, 16, died of cardiac arrest while playing basketball last Thursday, CNN affiliate WOOD reported. He'd had an enlarged heart, an autopsy found.
His wasn't the only sudden death among sports-playing U.S. high schoolers in the last two weeks. Matthew Hammerdorfer, 17, died playing rugby in Fort Collins, Colorado, due to cardiac arrest from a congenital heart defect. In North Carolina, 16-year-old Javaris Brinkley died of heart failure after playing basketball at a church Monday; he'd had a known heart condition, according to the Roanoke Rapids Daily Herald. And 17-year-old soccer and track star Sarah Landauer of Gainesville, Florida, collapsed at track practice; she died Wednesday, local news reports said; the cause of death has not yet been released.
Although four deaths in two weeks may seem like a lot, it's consistent with the national average for scholastic athletes, it does draw attention to questions that have been looming for years: Should there be more extensive health screenings before young people can participate in sports? And should schools be required to have defibrillators?
Some physicians are calling for more comprehensive screenings for all athletes. Dr. Roosevelt Gilliam, cardiologist at Healthcare Medical Group in Jonesboro, Arkansas, is part of a community-based effort to screen all athletes in his area for health problems.
"A more complete physical and more attention to details certainly is indicated, and I think that this is highlighted unfortunately by when we see the catastrophic events, such as the last two weeks," Gilliam said.
More and more countries, as well as the International Olympic Committee and other sports organizations, are requiring that athletes get a screening that includes an electrocardiogram (ECG) before participating in sports. This is a test that measures the heart's electrical activity; abnormalities may indicate an underlying problem.
But the latest research on the question of electrocardiography (ECG) has not found sufficient evidence to recommend that all athletes should have this testing.
A 2011 study in the Journal of the American College of Cardiology, led by Dr. Arie Steinvil of Tel Aviv University, looked at whether mandatory ECG had an effect on sudden death and cardiac arrest among athletes in Israel, which began requiring the test in 1997. Researchers found that mandatory ECG had no effect on the numbers of sudden deaths among athletes in the country.
Previously, an Italian study did find a reduction in sudden death. It suggested that in order to save one life, 33,000 athletes must be screened, at a total cost of about $1.3 million per life saved, Steinvil and colleagues wrote. That doesn't include the cost of further testing for those who have abnormalities in their ECG, which will be about 5% to 16% of athletes.
There are about 50 to 100 sudden deaths among athletes in middle, high school and college every year, said Dr. Marlon Rosenbaum, associate clinical professor of medicine and pediatrics at Columbia University College of Physicians & Surgeons.
"We're looking for uncommon events in large populations, and it's not clear how to do it," said Alfred Bove, cardiologist in Philadelphia, Pennsylvania, and past president of the American College of Cardiology.
The most common cause of sudden death among young athletes is hypertrophic cardiomyopathy, when the heart is thickened and enlarged, particularly in young, African American athletes, Gilliam said. This problem can be detected by an initial ECG screening, followed by an echocardiogram (an ultrasound of the heart) for diagnosis. People with it should generally not participate in competitive athletics or other strenuous activities, Gilliam said.
Another serious but rarer condition among young people is dilated cardiomyopathy, in which the heart is enlarged but the walls are thin. This is the condition that Leonard had, WOOD reported. In adults, it's the No. 1 reason people get defibrillators implanted, Gilliam said.
Family history and screening together can help doctors identify students at high risk of problems, he said. The American Heart Association has this 12-step guide for physicians to use in questioning young people before they participate in competitive athletics.
A major concern with ECG is false positives, meaning the test says there's something wrong when there is not. Athletic conditioning itself can affect the size of the heart and results of an ECG, Rosenbaum said. So just doing more screening may not be the answer.
"We're not putting a dollar value on life, here," he said. "What you have to understand is that if you do an ECG on 10 million adolescents one year, you have to put in place an infrastructure to do this year after year, you have to have guidelines of what an abnormal ECG is, you have to have guidelines about who can play based on it and who can't play based on it, and it has to be something that would be undertaken at a federal level."
But Rosenbaum and others do see value in ECGs, and there are community-based programs that provide ECG screenings for free. Gilliam's medical group screens more than 1,000 kids for a variety of medical problems, and does an ECG on every high schooler in the county who comes. All of the physician time is donated, the staff is all volunteer, and medical equipment is donated. The free physicals and ECGs will take place April 16 and 17.
At the collegiate level, there's a program at Arkansas State University, where one young man who was a wide receiver on the football team had a critical heart problem detected by the screening program. He had to have heart surgery and was instructed to stay off the field for one year. But when he came back to the team, he earned distinctions such as honorable mention for All-America wide receiver.
"He's sort of a face that many of us in our community now can put to our efforts as being someone who we have actually done a great service to. He's gone from someone who could have potentially have been a mortality or a fatality on the practice field, to now he is really considered one of the team's best players and leaders on their offense," Gilliam said.
In the future, with technological advancement, there may be easier and more inexpensive ways to look for heart problems. Bove envisions an echocardiogram with the same functionality as a stethoscope, but that's several years off, he said.
Given the conflicting evidence surrounding the ECG issue, Rosenbaum says a focus should be placed on responding to cardiac episodes when they happen. A key way to do that is to have an automated external defibrillator (AED) on hand. He supports having one in every school, as well as people trained on using them.
Parents have been lobbying Congress for years demanding that schools be required by law to have AEDs. The American Heart Association supports this measure, called the Josh Miller HEARTS Act. In 2009, the House of Representatives passed it, but it didn't get through the Senate.
But the devices are expensive: Between $1,500 and $2,000. And, as in the case of Landauer, defibrillators are not always sufficient to save a life.
Landauer, the track star who died Wednesday in Florida, had also collapsed in late February during training at the University of Florida, the local newspaper Star-Banner reported. But she had received medical clearance to return to athletics. On Monday, CPR and a defibrillator, which is kept in the school's gym, were unable to revive her, the Star-Banner said.