Screening programs say they're educating parents about the risks. "What we want to emphasize is, make sure your kid is heart-safe," said Dr. Jonathan Drezner, a sports and family medicine specialist at UW Medicine and medical director of the Seattle-area Nick of Time Foundation.
Enthusiasm for EKGs, which measure the electrical activity in the heart to detect abnormalities, grew after a 2006 study showed they lowered death rates among athletes in Italy. But research in other countries hasn't yielded similar results, and the Italian researchers recently were accused of refusing to share their data so it could be evaluated independently.
Some 60,000 to 70,000 U.S. teens were screened with EKGs in 2016, most by foundations created by families who lost a child to sudden cardiac death, said Sudman, who runs the online directory Screen Across America. It's unclear whether high school athletes face higher risk than nonathletes, so screening programs usually invite everybody.
Screenings typically are held in high schools and overseen by volunteer cardiologists, with funding from individuals and businesses including hospitals. A handful of hospitals and for-profit companies also run screenings.
It may be presumptuous to claim EKGs save lives, but parents often believe they do, said Sudman. "If I find a heart condition, I promise you there are parents who are thanking me for savings their kid's life," he said.
That perception is stoked by tragic stories in the media of children who died suddenly after never reporting a symptom.
Meanwhile, the drawbacks of EKGs are seldom depicted. As many as 1 in 10 EKGs detects a potential abnormality, and the emotional and financial toll of such a finding can be significant — especially when they turn out to be wrong.
Following a screening EKG and echocardiogram last fall, Daniel Garza, 16, a talented sophomore basketball player in San Antonio, was told he had hypertrophic cardiomyopathy, a thickening of the heart muscle and the most common cause of sudden cardiac death in young people. He was advised to quit all exercise, at least temporarily.
"We were shocked, just shocked," said his mother, Denise. She said her son became depressed when he couldn't play the sport he enjoyed and excelled at. "He came home and cried himself to sleep. He said, 'Mom, why did God give me this gift to take it away?' "
The Garzas traveled to the Mayo Clinic in Rochester, Minn., where further tests indicated his enlarged heart was a benign condition known as athletic heart, a result of intense training. His mother estimates that correcting the misdiagnosis cost more than $20,000, including medical costs, travel and lost work.
Daniel has returned to the basketball court. Still, Denise Garza said the emotional toll was rough: "It was one of the hardest things my family has ever endured."
Several cardiologists said they often see cases like this — or worse. Even after follow-up testing, it can be unclear which cases are life-threatening, so kids with low risk could be restricted from exercise or given life-altering interventions such as implantable defibrillators, surgery or anti-arrhythmic medications.
Medical groups have wrestled with the issue. The American Heart Association and the American College of Cardiology recommended in 2014 against mass ECG screening, noting that sudden cardiac death is rare in teens and false positives generate "excessive and costly second-tier testing." ECGs also miss at least 1 in 10 cases of hypertrophic cardiomyopathy and more than 9 in 10 cases of congenital anomalies, the second-most-common cause.
But the medical panel accepted voluntary screening "in relatively small cohorts," if there's physician involvement, quality control and a recognition of unreliable results and ancillary costs.
Efforts are underway to improve the accuracy of the screening programs. Some are adding echocardiograms, which use ultrasound to produce images of the heart, to assess potential abnormalities. Advocates say false positives have dropped as a result of better interpretation guidelines, known as the Seattle Criteria, which are expected to soon be endorsed by cardiology societies in revised form.
But the criteria aren't perfect, and there's a "giant gap" in training cardiologists to use them, said Drezner, one of the developers. He's also a medical adviser for Parent Heart Watch, a consortium of foundations. "If I was a parent, I'd want to know about the experience of the (cardiologists) and what they're going to do to help my kid if they have a positive screen."
One problem with EKGs is a lack of good data.
"There's no evidence we have that [EKG] screening saves lives," said Dr. Jonathan Kaltman of the National Heart, Lung, and Blood Institute. "There's never been a controlled clinical trial, which is the only way to answer that question."
At the urging of screening advocates, the NIH partnered with the Centers for Disease Control and Prevention to rigorously track cardiac deaths as part of a Sudden Death in the Young Case Registry. So far a handful of states and counties have joined the effort, which helps local health departments collect better data. The goal is to standardize death investigations and get a firm handle on how often kids die from heart abnormalities as well as the role of factors such as genetics. Initial findings are expected to be available in about two years. The NIH is also funding three university-based research groups to answer key questions about sudden cardiac death in the young.
Some screening organizations are getting behind a nascent initiative with the Cardiac Safety Research Consortium to harness their own screening data for research. It would require standardizing their practices and tracking outcomes, which organizations aren't now equipped to do.
"Screening is happening. We can't avoid that," said Dr. Salim Idriss, director of pediatric electrophysiology at Duke University and co-chair of the initiative. "We have a really good opportunity to get the data we need to make it better."
Separately, the UT Southwestern Medical Center in Dallas recently began a four-year pilot study involving athletes and band members at eight high schools to determine the feasibility of a full-scale randomized controlled trial.
A valid finding on the overarching question of whether EKG screening saves lives could require at least 800,000 participants and a cost of $15 million, said Dr. Benjamin Levine, a cardiologist and the lead researcher.
The pilot is partly a response to legislation that would mandate EKGs for student athletes in Texas. A similar bill was also introduced in South Carolina. Both bills failed, but it's expected there will be more attempts to mandate EKGs, leaving state legislators looking for better guidance.
"We're not going to solve this by having more debates, but by having more data," Levine said.