Irish golfer Rory McIlroy has revealed he has "a bit of an irregularity" with his heart which requires regular scans.
The four-time major winner, who took a four-month break to recover from a rib injury, told the Daily Telegraph that the “irregularity” is possibly the result of viral infection he suffered 18 months ago.
"The rib's fine, no problems whatsoever – I had an MRI scan on my thoracic spine and all was OK," McIlroy said.
"But I've got a bit of an irregularity with my heart that I have to keep on top of.
"I have a flat T-wave and I’ll have to get an echo [cardiogram] on my heart every six months and an MRI scan every year.
“I suffered a really bad viral infection in China 18 months ago and they told me that’s the reason that I have this thickening of my left ventricle and there’s a bit of scar tissue. For now, I just need to stay on top of it and have to stay fit. Hey, I was planning on doing that anyway.”
McIlroy, 28, has slipped to 11th in the world rankings in the last year, but he is confident he will be bounce back as the world's best golfer.
"I don't care about the world rankings. I think about number of wins, the ability of the players against me, the number of majors the others have. I don't feel I need to compare myself to anyone else, because I know what I can do. I'm not hung up on it."
He added: "It's nice to be world No 1, sure, and I will get back there, but it's all about winning tournaments. And I will give myself the best chances this season."
McIlroy will return to the golf course in the Abu Dhabi Championship on Thursday.