The 48-year-old, who has competed for Australia in triathlon three times before, will race the London Olympic course starting and finishing in Hyde Park.
Laidlaw, who has heavily calcified arteries and must not raise her heart over 80 per cent of its capacity, was told by doctors to stop competing in triathlons.
The sportswoman did not dwell on the negatives of the situation she found herself in, instead focussing on what she could do.
PerthNow Digital Edition.
Your local paper, whenever you want it.Get in front of tomorrow's news for FREE
Journalism for the curious Australian across politics, business, culture and opinion.
READ NOW‘They said I have to keep my heart rate down so I don’t have a heart attack basically’