Dodgers’ Kenley Jansen off medication for heart ailment and 25 pounds leaner

Kenley Jansen has experienced more mood swings than usual this offseason. Not that the Dodgers closer had a bad winter.

The procedure to address his atrial fibrillation in November — his second ablation in six years — was declared a success. He’s no longer on medication for the ailment and has been cleared to pitch without restrictions — even in Denver’s thin air.

Jansen eliminated sugar and carbs from his diet, and though the sacrifice has helped him shed 25 pounds since the end of the season, purging ice cream has been as challenging as escaping a bases-loaded jam.

“It was a struggle…but I did it,” Jansen said at his team’s annual FanFest at Dodger Stadium on Saturday. “I did it. It kind of messed up right at Christmas, when I had rice for the first time. But now I’m watching what I’m eating.”

Baseball did not prompt Jansen’s lifestyle adjustment, making this transformation different than the typical “best-shape-of-my-life” spring account. His basic well-being was enough. His doctor told him his heart will never be 100% — 95% is the ceiling — but he figured losing weight could only help. So he did and weighs his lightest since 2012.

“You see how your body feels and all [that] good stuff that when you put it in your body, it’s not good for my heart,” he said. “So let’s worry about health first. I want to take care of my heart. I don’t want to do another surgery, man, on that heart. So I got to take care of myself.”

He also plans on attacking spring training differently this year. Instead of taking the laid-back approach he employed last spring, Jansen said he will pitch more. Jansen didn’t pitch in a Cactus League game until March 9 last year. It was one of two appearances scheduled for him, a decision the Dodgers made to curtail his use after heavy workloads the previous two seasons. But Jansen felt tightness in his hamstring before his debut and was scratched.

The hamstring injury was considered minor but could have had a significant effect on his season. Jansen suggested Saturday that he created “bad habits” when his velocity wasn’t the same last season. Those habits produced mechanical problems. His heart condition, which surfaced in August, complicated matters. The result was a 3.01 earned-run average, a 4.03 Fielding Independent Pitching mark, and 13 home runs allowed in 71⅔ innings during the regular season before posting a 1.69 ERA in 10⅔ playoff innings.

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Most relievers would consider the All-Star season a resounding success. Jansen’s grading curve — after two of the most dominant seasons for a reliever in recent history — was different.

“I’m not happy with the year that I had last year,” Jansen said.

Dodgers manager Dave Roberts wondered if Jansen’s weight loss could have an effect on his velocity — some plumper pitchers in the past have claimed the extra weight is a good thing — but insisted Jansen’s velocity will not dictate his success.

“We’ve seen it with Kenley,” Roberts said. “It’s not always the velocity. It’s the late movement. And so whether he’s throwing 94 [mph] or 90 and it’s straight, he’s a different pitcher, whether he’s throwing 90, 94 with that late cut. So we’ll see.”

The Dodgers will continue to rely on Jansen to anchor a bullpen that added Joe Kelly this offseason and had Pedro Baez emerge as one of baseball’s best relievers over last season’s final three months.

“Every year you want to get better,” Jansen said. “Even if I have a good year this year, next year I want to get better. As long as I play this game, I want to be better every time I get on that mound. I want to be more mature, I want to be better, and that’s what makes you great.”

jorge.castillo@latimes.com

Twitter: @jorgecastillo