What is on Bronny James' arm? Explaining the heart device worn by LeBron's son after cardiac arrest

Less than five months ago, it was impossible to know when or if Bronny James would be able to resume his basketball career. After LeBron James' son suffered cardiac arrest and was hospitalized, the initial focus was entirely on getting him back to full strength and a normal life. 

From the start, James maintained that he planned to continue playing basketball. USC made sure to be cautious with his recovery, sitting him out for the first month of the season, but James has hit every marker along the road to a return.

While that caution may result in some early minutes restrictions, James will take the ultimate step in his recovery when he takes the floor for the Trojans' matchup with Long Beach State on Sunday. 

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Here's what you need to know about the special arm band James is wearing and what purpose it serves after his heart scare in July.

What is on Bronny James' arm?

James is wearing a device on his arm that monitors his heart rate. He was seen wearing it during practice and warmups in the weeks leading up to his USC deut.

Bronny was a full participant in practice for the first time this season 💪 (via @FredoCervantes) pic.twitter.com/CuUAfhLjFT

— Overtime (@overtime) December 7, 2023

Not many details are known about which exact device James has, but it's not uncommon for athletes who suffer cardiac arrest or similarly serious heart-related incidents to have their heart monitored.

Doctors implanted a type of defibrillator to monitor the heart of USC forward Vincent Iwuchukwu, who suffered cardiac arrest a year before James joined the team. The device also allowed the Trojans' medical staff to keep tabs on Iwuchukwu's heart rate in the event there was an abnormality while he was practicing or playing in a game.

Similarly, officials will simply be able to monitor James' heart activity and ensure there are no signs of anything abnormal when he's on the court. After such a serious scare, it's nearly impossible to take too many precautions considering James is still just 18 and hasn't played in an actual game since the incident.

What happened to Bronny James?

James suffered cardiac arrest during a five-on-five practice at USC in late July. He was revived at the scene and hospitalized in the intensive care unit, but he recovered quickly enough to be released within three days.

Doctors determined that the cause of James' collapse was a congenital heart defect, which is considered treatable. By all indications, James has not run into any major obstacles along his recovery. Returning in time to start the season was not considered very realistic, and USC coach Andy Enfield recently called it "incredible" that James is even able to play three-fourths of the season. 

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Enfield confirmed to reporters that James will come off the bench and start the season on a minutes restriction, but just being available for USC is a colossal step in the right direction just months removed from a life-threatening incident.

James can seek inspiration from Iwuchukwu, who returned to play in 14 games last season and remains one of the Trojans' key role players. Former Florida and Kansas State standout Keyontae Johnson, who shined in last season's NCAA Tournament, also charted a path for James by working his way back from an on-court collapse while with the Gators.