Why is COVID-19 causing heart inflammation, or myocarditis, in athletes? Experts weigh in.

Researchers are learning more about the long-term effects of having COVID-19 with each passing day, and one aspect that keeps coming up is that athletes are struggling with a potentially serious heart condition after having had the virus.

University of Florida star forward Keyontae Johnson, who collapsed on the basketball court during a game on Dec. 12, has reportedly been diagnosed with myocarditis, a form of heart inflammation that has repeatedly been linked to COVID-19, which he suffered from during the summer.

University of Florida star forward Keyontae Johnson, seen here on Dec. 21, collapsed on the basketball court during a game earlier this month — reportedly the result  of COVID-19 related myocarditis. And he's not the only athlete to have experienced this medical issue. (Photo: Mary Holt/Icon Sportswire via Getty Images)
University of Florida star forward Keyontae Johnson, seen here on Dec. 21, collapsed on the basketball court during a game earlier this month — reportedly the result of COVID-19-related myocarditis. And he's not the only athlete to have experienced this medical issue. (Mary Holt/Icon Sportswire via Getty Images)

But Johnson is far from the only athlete to struggle with heart inflammation in the wake of the coronavirus. In August, Georgia State quarterback Mikele Colasurdo announced on Twitter that he was unable to play football this season after he was “diagnosed with a heart condition as a result of my COVID-19 infection.” Red Sox pitcher Eduardo Rodriguez also struggled with myocarditis after having had the virus. So did University of Miami defensive back Al Blades.

What is myocarditis?

Myocarditis is an inflammation of the heart muscle, known as the myocardium, according to the Mayo Clinic. The condition can affect your heart muscle and your heart's electrical system, and reduce its ability to pump. As a result, “patients can struggle with fast or abnormal heart rhythms, called arrhythmias,” Dr. Thomas Russo, professor and chief of infectious disease at the University at Buffalo in New York, tells Yahoo Life.

Myocarditis is usually caused by viral infections. “It happens more often with some viruses than others,” Dr. Richard Watkins, an infectious disease physician and professor of medicine at the Northeast Ohio Medical University, tells Yahoo Life. He lists the coxsackievirus (which can cause hand, foot and mouth disease) as being a more common culprit, while influenza and HIV less so.

The symptoms of myocarditis include the following, says the Mayo Clinic: chest pain, fatigue, shortness of breath and rapid heart rate (arrhythmias).

Myocarditis can be severe, Russo says, adding, “You can have a stroke or heart attack and die.” But the condition improves on its own in many cases and people can have a complete recovery — they’ll just often have to avoid competitive sports for up to six months, Russo says. In some situations, though, medications and even a mechanical heart pump may be needed, the Mayo Clinic says.

But what’s the link between myocarditis and COVID-19?

That connection is unclear at this point, Watkins says.

It may simply be that COVID-19 is just another virus that causes cause inflammation, infectious disease expert Dr. Amesh A. Adalja, senior scholar at the Johns Hopkins Center for Health Security, tells Yahoo Life. “It’s an inflammatory response that focuses on the heart that happens with many different viruses, and COVID-19 is one of those,” he says.

But, Russo points out, this may be more common with COVID-19 than many people realize.

A study published in JAMA Cardiology in July conducted heart MRIs on 100 patients who recently recovered from COVID-19 and found that 60 of them had myocarditis. Even scarier, the inflammation was independent of preexisting conditions, severity of COVID-19 and their overall course of illness.

“This is something that we as medical professionals are really worried about,” Russo says. “Most people look at getting COVID as you either live or die, but the reality is that it’s far more complicated than that.”

Russo points out that “virtually every organ in the body can be affected by COVID-19,” including the heart, lungs, brain and kidneys. And myocarditis as a lasting side effect could be a result of this.

As for why myocarditis been detected in high-level athletes, it may simply be that they’re monitored a little more closely than others. “High-level athletes often have a lot of testing done to them, and that can pick up myocarditis,” Adalja says. It also may be that athletes notice the symptoms more, given that they’re regularly taxing their bodies, Russo says.

This can happen to nonathletes too, Dr. Jason Womack, the chief of the division of sports medicine at Rutgers Robert Wood Johnson Medical School and a team physician with Rutgers Athletics, tells Yahoo Life. “If anybody has had COVID-19 and then later developed symptoms like exercise intolerance or chest pain with activity, those would be reasons to seek a cardiac consultation,” he warns.

Overall, though, Russo says that “we don’t completely understand who gets myocarditis from COVID-19, the magnitude of the risk and the magnitude of damage.”

Russo urges people who have had COVID-19 to certainly be aware of the risk of myocarditis, noting, “Everyone could potentially be at risk for these types of complications.”

For the latest coronavirus news and updates, follow along at https://news.yahoo.com/coronavirus. According to experts, people over 60 and those who are immunocompromised continue to be the most at risk. If you have questions, please reference the CDC’s and WHO’s resource guides.

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