Premature heartbeats can occur often or in rapid succession, causing the “fluttering” feeling that Harbaugh spoke of in the press conference. The term “sinus rhythm” used by Harbaugh refers to the normal rhythm of the heart.

Harbaugh said he “could tell there were some irregular beats in his heart during the game.” He said he received intravenous fluids and an EKG test from the Chargers' athletic training staff.

“I know a lot about it, so I just wanted to see what the pulse was,” Harbaugh said. “I'm not good at taking my own pulse. So they just took the pulse and it was the arrhythmia. But I felt like we were fine, and then they just said, “No, we need to do an EKG.”

“Trust the doctors,” he continued. “If you don’t trust your doctors, who will you trust?” I always thought that. And then when I got back to the locker room, the paramedics came and did an EKG. They said it was back in the sinuses.” Rhythm, and I said, “I'm fine.” So I'm back out there on the field.”

Harbaugh returned to the sideline as coach for the remainder of the game.

Does Jim Harbaugh have a history of heart problems?

The former San Francisco 49ers coach said he has suffered from cardiac arrhythmias before.

“I had a couple of ablations, one in 1999 and one in 2012,” he said. “And I will always remember the 2012 game because it was during the Monday night game, Colin Kaepernick and the 49ers versus the Chicago Bears, and Colin had a great night that night.

“After the game I was examined and ended up having an ablation because it didn’t get back into rhythm.”

Harbaugh joked that he was “2-0 with cardiac arrhythmias” after the 49ers game in 2012 and Sunday's game against the Broncos.

According to the AHA, ablation is a procedure in which radiofrequency energy, similar to microwave heat, destroys an area of ​​heart tissue, causing irregular heartbeats and helping to restore the heart's natural rhythm.

“I kind of felt it last night,” Harbaugh said. “But I wasn’t really sure. But yeah, sometime after the pre-game warm-up. Just like in 2012. It was like I kind of felt it during the pregame warmup.

“And I haven’t felt it since 2012. It didn't happen. But in the operation in 1399, 13 years later, the procedure had to be done again, so I thought I was approaching the 13-year mark, and I did. “I'll need another one at some point.”

John Harbaugh left his press conference after learning about his brother

Jim Harbaugh said Chargers general manager Joe Hortiz reached out to Jim's brother John and told him about Jim's situation. John then called her parents to inform them.

The Baltimore Ravens' 30-23 victory over the Washington Commanders had ended while the Chargers' game was still going on. John Harbaugh was commenting just after the game when he learned that Jim had left the sideline.

According to The Athletic, John then abruptly left the press conference and called to check on his brother.