Jansen, 23, was placed on blood thinners for three weeks, which will keep the right-hander sidelined for that long plus two days to get the drugs out of his system.
"It a little frustrating," Jansen said. "But at the same time you've got to take care of your heath first, because without your health, you cannot do anything. I really want to get out there and pitch, but I can't right now because it's too dangerous. Right now it's health first and baseball second because I want to have a long career in this game."
Trainer Stan Conte said that the club spoke with seven cardiologists from across the country, some of whom thought the blood thinners weren't necessary and others who thought the opposite. So he and his staff took the precautionary route after getting formal exams from two Los Angeles cardiologists, Dr. Tony Nguyen from White Memorial Medical Center and Dr. Sumeet Chugh from Cedars-Sinai Medical Center.
Jansen said he first started feeling symptoms about four hours before game time on Tuesday after he was done with his conditioning routine, but there was no dizziness. He didn't let anyone know about the fluttering sensations in his heart until after his seven-pitch save, when he told Conte and manager Don Mattingly.
It was Jansen's first ninth-inning save opportunity since May 23. The 6-foot-5, 257-pound Jansen, converted from a catcher to a pitcher in the minor leagues a couple of years ago, was summoned in to close it out because regular closer Javy Guerra had pitched three days in a row.
The medication Jansen was given at the hospital didn't work, so he was anesthetized for about 10 minutes and underwent cardio conversion — a process in which electricity is used to shock the heart and get it back into a normal sinus rhythm.
"I wasn't scared," said Jansen, who has no previous history of heart-related problems. "It's just that when they gave me that EKG and they told me I had to go to the hospital, I thought: 'Hey, what's really going on?' Then when they kept me in there (another night) and told me what's going on, that kind of scared me a little bit because of the way my heart reacted after they put the medicine in. Then they let me know that a few players had this before, so that kind of calmed me down a little bit."
The issue was not the atrial fibrillation that caused his Jansen's heartbeat to flutter in an abnormal manner, but the aftercare required for his condition, according to Conte — who emphasized that Jansen is not having any heart problems and may not the rest of his life. He'll just have to change his eating habits and stick with more healthy choices.
"It's serious enough to put Kenley on the DL," Mattingly said. "It's really all about him, making sure that we don't take any chances with his situation."
There will be no physical restrictions on Jansen, and he will still do regular bullpen sessions before batting practice. In fact, he threw one on Friday and did his normal running, a day after being released from White Memorial.
Once BP starts, however, Jansen has to leave the field because it could be dangerous if he gets cut by a hit or thrown ball. During the game, he has to remain in area of the bullpen that is under the left field pavilion with a helmet on — another precaution.
Jansen has appeared in 34 games this season, going 1-1 with a 3.65 ERA and 61 strikeouts in 37 innings. He currently has a 16-inning scoreless streak over his last 14 outings since coming off the disabled list June 18, and has allowed only three hits in 51 at-bats during that stretch.
The Dodgers filled the vacant roster spot by recalling right-handed reliever Josh Lindblom from Triple-A Albuquerque.