Bronny James, cardiac arrest and young athletes: What you need to know

Cardiac events are not uncommon and often fatal. But in the right place with the right training, lives can be saved.

On Monday, University of Southern California freshman basketball player Bronny James, the 18-year-old son of NBA star LeBron James, suffered a cardiac arrest while working out at the USC campus. A statement from a family spokesperson said Bronny James is in stable condition and out of the intensive care unit.

USA TODAY Sports spoke with Dr. Satyajit Reddy, a cardiologist, echocardiographer and sports medicine specialist at the Mayo Clinic, and other experts to learn more about cardiac arrest.

Here's what to know:

What can cause a cardiac arrest?

A cardiac arrest occurs when the heart suddenly loses its normal rhythm and stops pumping blood, according to the Sports Institute, part of the University of Washington School of Medicine system. That's different from a heart attack, which refers to when an artery is blocked, preventing blood and oxygen from reaching the organ.

How common are cardiac events?

Reddy said cardiac events can happen to anyone, not just elite athletes.

However, Reddy noted, “Athletics puts your body, and heart in particular, at higher intensity, and there's a lot of demand on the heart when you're exercising. As a result, it can lead to higher heart rates, higher blood pressure, higher inflammation through your system, and it can also lead to electrolyte abnormalities, which can exacerbate an underlying condition and cause cardiac arrest."

Sudden cardiac arrest is the leading cause of death among young athletes in the United States, with approximately 100 to 150 occurring during competitive sports events each year, according to a 2016 estimate from the American College of Cardiology. In the general population, the AHA reports more than 350,000 out-of-hospital cardiac arrests each year, of which nearly 90% – approximately 320,000 – are fatal.

Cardiac arrest affects the American population unevenly, and affects different types of athletes in different ways, Reddy said. It's more common among basketball, football and soccer players. It disproportionally affects men and athletes who are of Afro-Caribbean descent.

"Even with all the proper screenings, some people can still have sudden cardiac arrest," Reddy said.

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What steps are key to saving a life in a cardiac event?

An action plan is critical, Reddy said, and that includes “educating all those who are involved − the players, the athletic trainers, coaches and families − how to identify what cardiac arrest looks like.”

Checking someone's pulse through their arm or neck can help a bystander determine if someone is undergoing cardiac arrest. If there's no pulse, the heart isn't working, said Dr. Laxmi Mehta, director of preventative cardiology and women's cardiovascular health at the Ohio State University Wexner Medical Center in Columbus.

But even the most experienced medical providers may have trouble locating a pulse. Dr. Lance Becker, professor at the Feinstein Institutes for Medical Research and chairman of emergency medicine at Northwell Health, suggested in a January interview that people use the "No-No-Go" approach: 

• No consciousness: The person isn't awake.
• No breathing: The person isn't breathing, or isn't making regular breaths. 
• Go! Start chest compressions.

Knowing how to administer high-quality cardiopulmonary resuscitation, or CPR, is a necessary part of the plan, Reddy said. The main goal of CPR is not to restart the heart during cardiac arrest, experts say, and it rarely does. Chest compressions are meant to imitate the heart's function of pushing blood to organs of the body. 

"You're helping the heart by reacting as a pump," Mehta said in a January interview with USA TODAY. "The chest compressions allow circulation throughout the body, hopefully restoring blood flow to the organs." 

It's also important to know where automated external defibrillators, or AEDs, are located and how to use them, Reddy said.

“The more coordinated and more efficient you are in those things, the chance of survival after these events goes up. That's the only thing that really moves the needle in terms of improving outcomes with sudden cardiac arrest," he said.

When CPR is used, the survival rate is 11.2%, and when an AED is used, the survival rate increases to 41%, according to the Cardiac Arrest Registry to Enhance Survival, an online database by the Centers for Disease Control and Prevention and Emory University.

The sooner the action plan is executed, the better the result. “As every second goes by, the blood not getting to the brain can lead to irreversible damage,” Reddy said.

How CPR could have made a differencewhen Bronny James suffered cardiac arrest during a workout.

What are the next steps for patients following a cardiac event?

After the patient is stable, doctors will begin searching for the cause using an electrocardiogram (measuring electrical signals for heart function), echocardiogram (ultrasound of the heart) and MRI of the heart.

But Reddy said it’s important to ask the patient a series of questions: How had they been feeling? Had there been concerning symptoms of exercise? Any chest discomfort, palpitations, lightheadedness? What happened just before the event itself? Did the person take any supplements?

“Getting a good history from the athlete that survived is very important,” Reddy said. “For a lot of these young athletes, this may be their first manifestation of a cardiac issue, but if their older siblings or their older family members have had cardiac issues, it can hint towards issues with them. So getting a good family history is another really important thing that we do after these events.”

Can you fully recover after a cardiac arrest?

It begins with the cause of the cardiac arrest, Reddy explained.

“If the risk factors that led to their event are reversible or modifiable, then sometimes we're OK,” he said. “We have a frank discussion with the athlete, with the family, and let them know the likelihood of this happening again. And we ultimately put it in their hands − with our guidance, of course − whether it's safe for them to return to sport.

"There are some instances where treatments can greatly reduce the risk of another event happening," Reddy said. "And there's some circumstances and some conditions where that is not the case.”