New Zealand Olympic champion Nathan Cohen has today pulled out of the World Rowing Championships with a heart problem.
Karl Manson, younger brother of Robbie Manson, will replace Cohen in the men's quadruple scull at the 2013 World Rowing Championship regatta in Chungju, Korea.
Cohen suffered from an episode of Supraventricular tachycardia (SVT) in yesterday's heats racing.
The 27-year-old has experienced an SVT episode prior to this, earlier this year in April during the Rowing New Zealand Winter Series racing at Lake Karapiro.
He was given the all clear to continue training and racing after being checked out by medical experts at that point in time.
In yesterday's heat Cohen experienced lack of strength and power as the race went on. The mens quad finished in fifth place in the heats.
Cohen explained what it felt like racing yesterday, saying: "It feels like once you're into the race, your heart isnt in rhythm, oxygen is running out, and you lose power, and become weaker and weaker as the race goes on. It feels like your dragging something behind the boat."
Cohen has only had minor episodes over the past few months, and is says it is well managed by limiting things which might set it off like caffeine.
While disappointed to not be able to contest the world championships regatta any further Cohen was pleased Manson is able to take his place.
"From a personal point of few, I've been training hard for the past ten months, but knowing that there is suitable replacement helps," he said.
"It's great to have a reserve here, so I dont have to run the risk of racing and it happening again. Karl will fit straight in, with silver at Under-23s a few weeks ago, the boat should keep its speed up.
"I could race tomorrow and be fine, but it's not worth taking any chances, as I could have another race tomorrow like I had yesterday.
"I don't want to let my crew down."
SVT is a common amongst endurance athletes, especially as they get older.
Manson will slot into Cohen's bow seat come the repechages tomorrow and will continue racing in the crew for the rest of the regatta.
For Cohen now it is about the short term goal of getting the body right before focusing too far ahead.
The 2013 World Rowing Championships run from 25 August to 1 September in Chungju, South Korea.