INDIANAPOLIS – Kasey Kahne has offered additional details about the health issues that will keep him from competing in this weekend’s Brickyard 400 at Indianapolis Motor Speedway, opening up in a Friday morning media teleconference.

Kahne also noted that the heat exhaustion symptoms he’s been battling over the past year were “definitely” a part of his decision to retire from NASCAR competition at the end of the season.

The Enumclaw, Wash., native was visibly drained following Sunday night’s Bojangles’ Southern 500, laying down on the pit wall after climbing from his car and remaining there for several minutes before going to the infield care center for additional treatment.

The cycle is one that has happened for Kahne several times since last season. In fact, he had to receive IV fluids for dehydration after his win at Indianapolis last July, sitting down at the side of his car during his victory lane interview out of exhaustion from the final laps.

Kahne’s battle with dehydration and an increasing heart rate ultimately led him to meet with three doctors this week, and their advice – combined with the toll Darlington took out of him and IMS’ penchant for extreme physical demands in the race car – led him to his decision to sit out this week.

“I didn’t start having problems until last year,” said Kahne, who will be replaced by Regan Smith this weekend. “I don’t really know why that is, and we’re trying to figure that out. I can’t control the temperature in my body, and my heart rate, at a certain point (late in the race). Once it gets to that point, there’s nothing I can do until I get out of the car. That’s why I’m not racing this weekend. I don’t want to create any more damage to myself.

“It’s just been a rough week. This was a really tough decision,” continued Kahne. “I would much rather be there than not, but at this point I have to just figure out how to finish these races, how to be able to go that long in a hot car in the environment that we’re in … between the air temp and the dew point degrees, just to control it all.”

Kahne pointed out that he prepared as well as he possibly could have going into the Southern 500, but it still didn’t turn out to be enough.

“I’ve been working hard on it,” he noted. “One thing I did going into Darlington was (that) I was very hydrated the four days leading up to the race, ate very clean, very good foods for hydration. I knew it was going to be a really hard race on me because I just understand that between the heat and the dew point degrees, if either one of them is high, I really struggle any more. So I was super hydrated. I was in really good condition going into the race. Had a great practice on Friday.

“And then about halfway through the race, I started getting to the point where I couldn’t drink any more. Once I can’t drink any more, I’ve already lost a lot more fluids than what I was able to put in.  That’s why I can’t drink any more; it will start coming back out. I keep drinking the most that I can throughout the rest of the race, but it just gets super hard. My body keeps sweating so much that I have absolutely nothing left by the end of the race.”

While Kahne shot down any notion of feeling like a danger to others on-track during the closing stages at Darlington, he did admit he was concerned for himself at times.

“It was really hard to keep my eyes open and see. I was struggling to do that,” Kahne recalled. “I was trying to control my heart rate because it was so high. I basically just kind of laid in the car and drove around the corners. I had to control the car and just to try to do as little as possible, so my heart rate would go down because it was so high.

“At that point all I’m doing is focusing on my body and my health, not on what I should be actually focusing on, and that’s racing.”

As far as when he’ll return to the race car, Kahne wasn’t ready to put a definitive date on that either.

“(Right now) I’m just taking it one race at a time,” he said.

The Monster Energy NASCAR Cup Series heads to Las Vegas Motor Speedway next weekend, where temperatures look to soar past 100 degrees.

“That definitely worries me,” Kahne said. “But if we can come up with a way for me to stay hydrated throughout the race and we feel really comfortable with it, then I’ll be in Las Vegas.”