Detecting with HEARTS

Sudden cardiac death in children is rare and stems from undiagnosed heart conditions. Dr. John Higgins is working to improve diagnostic practice for middle schoolers

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By Ivy Ashe
Population Health Scholar
University of Texas System
PhD Student in Journalism
UT Austin Moody College of Communication

 
 

There was a problem in Houston.

Dr. John Higgins, associate professor and sports cardiologist with McGovern Medical School at The University of Texas Health Science Center at Houston, realized this shortly after moving to the city fresh out of a cardiology fellowship at Brigham & Women’s Hospital in Boston.

A distance runner who has completed 13 marathons, he was beginning to get more involved with sports cardiology.

“We became aware there were kids that were having sudden cardiac deaths, or SCDs, when they were playing sports,” Higgins said. Within the span of a week that year, he recalled, two teenage girls in Houston had suffered SCD while playing basketball.

“It got me thinking, ‘Well, we have to do something to protect these kids,” Higgins said.

SCD refers to an unexpected death in a person who previously did not display any signs of a heart condition. Overall, it is a rare occurrence, affecting one to three people per 100,000. It is most common in athletes, particularly African-American basketball players, and is the leading cause of death for young athletes.

In 2009 Higgins, who is also affiliated with Memorial-Hermann Hospital, launched the Houston Early Age Risk Testing & Screening (HEARTS) program. HEARTS aims to improve detection practices for an underdiagnosed group: middle schoolers.

Many of the conditions that contribute to SCD are genetic, and unlikely to be detected by routine physicals. To the extent that children typically receive screenings for underlying heart conditions, it is via the basic tools of completing a family medical history and a physical examination. This, Higgins said, is akin to searching a needle-filled haystack by hand.

“You might pick up a few needles and you might jab your hand on a few,” he said. “But you’re going to miss most of them.”

The HEARTS program tested sixth-graders in the Houston Independent School District for heart conditions using electrocardiograms (ECG) and echocardiograms.

ECG is like using a metal detector to find needles, Higgins explained. Family history and physical examinations can detect about 10 percent of conditions, he said. ECG screenings, although they involve more equipment and therefore are more costly, bring that number up to 95 percent. The American Heart Association recommends only the family history and physical before sports participation, but organizations such as the International Olympic Committee and the National Basketball Association require ECG and stress ECHO screenings for all athletes.

Given the importance that the NBA places on ECG screening, it’s no surprise that initial funding for HEARTS came from the Houston Rockets, with one team executive even bringing his daughters to be tested by the research group.

Once the project had its funding, 254 students from three middle schools were screened via a 15-minute procedure including both the physical and family history as well as ECG and echocardiogram. Most students were African-American or Hispanic.

Several participants were diagnosed with obesity and Stage 2 hypertension. Others had conditions that could lead to SCD, such as Wolff-Parkinson-White Syndrome, coarctation (narrowing) of the aorta, and aortic arch dilation.

In some cases, the findings required additional treatment. One student with aortic coarctation had a stent placed, while another had transcatheter closure on an atrial septal defect (ASD). An ASD can lead to weakening of the right side of the heart if not treated.

Not all students with abnormalities had follow-up procedures, but this was because they left the school.

Higgins stressed the importance of screening at a relatively young age, as well as the need to screen both athletes and non-athletes. Middle school is a good starting point because students are beginning to get more serious about sports participation and their bodies are in a “peak growing phase.”

“As they get older and their hearts grow, the conditions manifest,” Higgins said. “It made sense that if they did have a heart problem that they didn’t know about, the combination of doing a lot more and more serious sports would bring it out.”

A first look at the data showed that the number of heart problems found in the athlete group was similar to that in the non-athlete group. Given that SCD in general was most common in athletes, these findings jumped out to the research group.

“Initially we were a bit puzzled, like ‘What’s going on here?’” Higgins said.

The very nature of having an undiagnosed condition means that a non-athlete student could be likely to get more out of breath during exercise, struggle more than peers, and then decide to quit entirely.

“As a kid you might think, ‘I’m not good at sports,’ so you might kind of select yourself out of the sport,” Higgins said. “These conditions are genetic; they’re born with them. If kids do have them, it would make sense they wouldn’t want to play sports.”

HEARTS has the funding to continue in more Houston middle schools, with a focus on learning more about undetected conditions across racial and ethnic groups, as well as the ongoing promotion of adding ECG testing as a required component of approval for playing sports.

Since the first round of HEARTS was completed, Higgins has started work on an overlapping area of research: how energy drinks such as Red Bull impact the cardiovascular system during exercise. He’s continued to advocate for changing the protocol for pre-sports clearance.

“Current history and physical misses most of the cases,” Higgins said. “What we’re doing right now does not seem to be working.”