Chargers head coach Jim Harbaugh said his brief exit during Sunday's win over the Broncos was due to a heart rhythm abnormality at the beginning of the game.
"It's called atrial flutter," Harbaugh told reporters. "I got into an episode today with it. Doctors checked me out and it got back into a sinus rhythm -- normal rhythm -- so, I came back."
Early in the first quarter, Harbaugh entered the blue medical tent before heading to the locker room. The team announced he was questionable to return due to an illness.
Harbaugh returned by the end of the quarter and finished the game on the sidelines. The 60-year-old coach said this wasn't the first time he's dealt with an irregular heartbeat while coaching.
"I had a couple ablations, one in 1999 and one in 2012," he said. "I'll always remember the one in 2012, 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, got checked out. Ended up having to have an ablation for that one because it didn't go back into rhythm, but 2-0 with arrhythmias."
Defensive coordinator Jesse Minter served as the Chargers' interim coach during Harbaugh's absence. He was faced with a decision during his time at the helm, electing to settle for a chip-shot field goal from the 2-yard line for the game's opening score.
The Chargers scored points on their next three possessions to secure a 20-0 lead entering halftime. They were held to just a field goal in the second half and surrendered 16 unanswered points, but ultimately fended off Denver's comeback, 23-16.
Harbaugh and the Chargers (3-2) will face the Arizona Cardinals as part of a Monday Night Football doubleheader in Week 7.