Why Some Young Athletes Suffer Cardiac Arrest

When Bronny James, the 18-year-old son of NBA star LeBron James, collapsed from cardiac arrest while practicing at the University of Southern California, it brought renewed attention to a leading cause of sports-related deaths in young athletes.

Sudden cardiac arrest in young athletes is rare. It’s estimated that 1 in 40,000 to 1 in 80,000 young athletes die from sudden cardiac arrest every year.

It often happens without warning. Most cases of sudden cardiac arrest in young athletes are due to underlying heart conditions that are genetic and go unrecognized, says Ivan Cakulev, MD, a cardiac electrophysiologist at University Hospitals Harrington Heart & Vascular Institute.

“Younger athletes can undergo medical screenings, but there’s no guarantee screenings can predict the risk of sudden cardiac arrest,” Dr. Cakulev says.

What is Sudden Cardiac Arrest?

Sudden cardiac arrest is an electrical malfunction that causes the heart to stop abruptly. It’s different than a heart attack, which is a circulatory problem caused by a blocked artery.

Sudden cardiac arrest causes the person to lose consciousness and stop breathing. It’s frequently called sudden cardiac death because many patients don’t survive. Quick response with CPR and especially with an automated external defibrillator is critical to restoring the heart rhythm.

What’s the Cause?

A number of conditions can elevate risk of sudden cardiac arrest in young athletes:

• A genetic disorder called hypertrophic cardiomyopathy (thickened heart muscle) is the most common cause.
• Inherited or congenital conditions of the heart or blood vessels that can reduce blood flow or affect the heart’s electrical impulses. A follow-up evaluation of Bronny James showed that a congenital heart defect likely caused his cardiac arrest.
• A blow to the chest that occurs at a particular point in the heartbeat cycle may cause the heart to stop, a condition called commotio cordis.

Who is At Risk?

Male athletes are at higher risk than female athletes and Black athletes are at higher risk than athletes of other racial groups. It’s also more common in basketball and football than other sports.

Are There Warning Signs?

Often there are no warning signs, but sometimes athletes may experience symptoms during physical exertion:

• Dizziness
• Shortness of breath
• Chest pain
• Unexplained fainting

How To Identify Athletes at Risk?

A thorough pre-participation medical exam is crucial, says Robert Flannery, MD, of the University Hospitals Drusinsky Sports Medicine Institute.

“A good pre-participation exam will cover questions about personal and family history, shortness of breath, feeling more tired than peers from the same workout and skipped or racing heartbeats,” Dr. Flannery says.

Family history of sudden cardiac arrest increases chances that a young athletes may have a similar heart problem. The American Heart Association and American College of Cardiology recommend a 14-item screening checklist that covers personal health, family history and potential symptoms during exercise.

An electrocardiogram can detect some heart problems that may put an athlete at risk, but they are not a good predictor of sudden cardiac arrest and are not recommended as routine screening.

Related Links

University Hospitals Harrington Heart & Vascular Institute is dedicated to providing the highest quality care for all patients.

The Congenital Heart Collaborative at University Hospitals Rainbow Babies & Children’s Hospital features a nationally recognized team of pediatric heart specialists including pediatric cardiothoracic surgeons and pediatric cardiologists.