Bronny James suffered cardiac arrest during a workout. How CPR could have made a difference
A recent, unexpected cardiac episode of NBA star LeBron James' son Bronny James sheds light on the dangers of cardiac arrest.

The 18-year-old was hospitalized after a cardiac event during a workout at the University of Southern California's Galen Center on Monday in Los Angeles. Following his hospitalization, James' family said he is in stable condition and out of the intensive care unit.

James' cardiac health scare echoes that of Buffalo Bills player Damar Hamlin, who suffered a cardiac arrest on the field during a January game against the Cincinnati Bengals. "Here for you guys just like you have been for me my entire process," Hamlin wrote to the James family on Twitter.

More than 356,000 out-of-hospital cardiac arrests occur annually in the U.S., according to the 2022 Heart Disease and Strokes Statistics report from the American Heart Association. Approximately 90% of them are fatal, and CPR is one proven method that can help combat the risks of cardiac arrest.

Here's what you need to know about the life-saving technique.

What is CPR?

Modern CPR, or cardiopulmonary resuscitation, dates back to 1960, when physicians William Kouwenhoven, Peter Safar and James Jude first recommended combining mouth-to-mouth rescue breaths with chest compressions. But as far back as the early 1900s, scientists discovered external chest compression could restore circulation in animal test subjects.

In the case of Hamlin, quick-acting trainers and first responders recovered his pulse and restored the footballer to a normal rhythm with CPR and defibrillation. A few days later, Hamlin was awake and neurologically intact.

The American Heart Association is the leader in teaching CPR and has a website to search for courses. Cost varies but is usually under $100 for basic certification.

Learning effective CPR requires a hands-on learning environment with a certified instructor, but there are some key points people should be aware of.

Start CPR as soon as possible during medical emergency

A timely start of CPR following cardiac arrest is critical.

Mortality increases by 10% for every minute that CPR is delayed. Even if 911 is called immediately, first responders can be minutes away. The best-case scenario is when cardiac arrest is witnessed, one person calls 911 and another initiates CPR.

If you are by yourself, call 911 on speakerphone, start CPR and the 911 dispatcher can guide you until EMS arrives.

Compression-only CPR can serve as alternative to mouth-to-mouth rescue breaths

CPR with mouth-to-mouth rescue breaths is considered superior to compression-only CPR, but amid increased awareness of viral respiratory illness, some individuals may be worried about giving rescue breaths.

Giving effective rescue breaths can be a difficult skill to master, even for CPR-certified individuals. Without proper positioning, mouth-to-mouth rescue breaths can be sent into the stomach instead of the lungs, for example.

For the average bystander, compression-only CPR for adults is recommended, as there is still some air exchange with compression-only CPR. However, for infants and children, the cause of cardiac arrest can be due to a severe breathing problem. If the person in trouble is your own child, give rescue breaths as you were trained in your CPR course.

Restart CPR as needed to stabilize blood flow

After 2 minutes of administering CPR, check for a pulse – but do it quickly. If you do not feel a pulse, if the pulse feels weak or if you aren't sure if you feel one, immediately restart CPR.

It takes multiple sequential high-quality external compressions with CPR to generate enough momentum to get the blood pumping from the heart to the brain. This momentum drops off immediately, however, the moment you stop doing compressions.

Use AEDs to aid CPR process

Hamlin was given an electric shock from a portable AED at the stadium the night he collapsed. AEDs, automated external defibrillators, are located at stadiums, shopping malls, airports, office buildings and other areas where large groups of people frequently gather. The defibrillators are used in just 6% of cardiac arrest cases, however, likely due to the public being unaware of them or uncertain of how to operate them.

AEDs are typically found inside small red, yellow or green boxes with a heart on them, and anyone can use them. Once the AED is turned on, the computer voice instructs the user what to do, including where to apply the pads that assess if a person with cardiac arrest has a rhythm requiring a shock or if more CPR is needed.