Rio Olympic Games gold medallist Kyle Chalmers will have heart surgery and miss July’s world championships.
The 18-year-old from Port Lincoln, South Australia, has supraventricular tachycardia which occasionally causes his heart to race.
It is not a life-threatening condition.
He withdrew from Australia's national short course championships in November on medical advice after experiencing symptoms just before his 100m freestyle final in Brisbane.
"We decided it was in Kyle's best long-term interest to get the surgery done sooner rather than later," Chalmer's coach Peter Bishop said.
