The Scot had to have his heart restarted in November last year after pushing himself beyond the limit during training.
The hospital treatment was required because his heart was beating irregularly and too quickly and he feels that commitment has shown him what he is capable of achieving.
"I think that was a boost if nothing else," said Jamieson, who finished runner-up to Germany's Marco Koch in his latest race, a 200-metre breaststroke at the Berlin International earlier this month.
"I think it shows just how much is being put into preparing for this summer.
"It's going to be the biggest race of my career and I need to make sure I'm in the best shape I can possibly be in to swim fast.
"Everything is going well. I am in the middle of preparing for qualification for the Games next month. The Games themselves are the big target for this year. I'm fit and healthy and everything is going to plan."
Jamieson next races at the Scottish Gas National Championships in Glasgow, which take place on April 5-8 at the Tollcross venue that will stage the Commonwealth Games.
He was back in his home city on Monday to encourage children to take part in sport and to switch on the Glasgow 2014 countdown clock. But he will continue to train in Bath until mid-July.
"I obviously need to qualify for the team first, but there will be a preparation camp with the rest of the swim team a week or two before the even starts and we will just come into Glasgow a day or two before the competition," Jamieson said.