An undiagnosed heart condition was the cause of James Williamson's death while sleeping at the Cape Epic mountain bike race last week, according to Williamson's partner Niki Fisher. Fisher travelled to South Africa with Williamson's family last Wednesday, where she spoke with the race doctor after an autopsy was performed on the 26-year-old.
"It appears Jimi had a 'heart condition' - where the second chamber of the heart did not push the blood out properly - so to compensate, Jimi's ventricle grew larger," said Fisher. "This was a genetic condition. It had nothing to do with his riding."
Williamson's participation in the grueling 722 kilometre mountain bike stage race wasn't necessarily a factor in the failure of his heart, according to Fisher. As an endurance mountain biker and the 2008 Solo 24 Hour World Champion, Williamson was no stranger to competing at challenging races like Cape Epic.
"It could have happened to him as he was sitting at the computer, or just lying in bed," she said. "The doctor thinks if anything that Jimi's fitness was positive and unlikely to have contributed or encouraged the problem."
Doctors told Fisher that it was possible even had Williamson had his heart tested in recent years that the condition might not have been revealed. She recalled the doctor's hypothesis on the events that caused Williamson's heart to fail.
"The doctor explained in detail what he thinks might have happened during the night. Jimi was lying comfortably on his stomach, and his heart beating would not have done what it was meant to do which is what killed him. He would not have known this and would have died peacefully in his sleep."
The post mortem found no blockages and Williamson's potassium levels, which could indicate electrical problems with the heart, were normal. "Nothing wrong in any other way," added Fisher.
The weekend's Mont 24 Hour mountain bike race in Canberra, Australia was essentially shortened by one hour to 23 hours in order to accommodate a tribute ride to Williamson. Competitors at the event rode a shortened loop, taking about 30 minutes, as a tribute to Williamson with the race officially starting at 1 PM AES.