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FOX 2 - She's a woman with a passion for fitness, but that came to a screeching halt when she collapsed on her 31st birthday and doctors discovered something that shocked them.
They diagnosed her with a genetic heart condition that often causes sudden death.
"I was not the poster child for heart disease," said Kristy Sidlar.
Sidlar shocked her doctors when she suddenly collapsed in her 20s.
"Originally I was teaching a fitness class and I passed out and so I was misdiagnosed then," she said. "I mean, I don't blame them for what they knew at the time. It was the right diagnosis."
It wasn't until she fainted on the side of the road tree years later - while training for a triathalon - that doctors realized something was seriously wrong.
"He looked at my chart and he looked at my echocardiogram and my X-rays, and he said, 'I honestly don't know how this woman can walk down the hall.'"
Her heart was failing. Sidler was diagnosed with a heart condition that often causes sudden death in young, healthy people.
"One in three women die of heart disease and we don't realize how prevalent it is," she said. "We hear about cancer, unfortunately, much more than we hear about heart disease. They're all important. They all can be very deadly - but 80% of heart disease is preventable."
While Sidler couldn't prevent her condition, a focus on wellness allowed her to recover faster than most.
Kristy Sidler
"I do believe that if you're stressed, if you're sick, if you're not sleeping well, if you're worried about your finances, if you don't have the means to go to the doctor, you can't be as resilient," she said.
Her support system and balanced lifestyle kept her strong leading up to her transpant. Now, she has a healthy heart to go with her new lease on life.
"I knew life would be great after the transplant - I just didn't know how great it could be," she said. "The first time I was able to run on the treadmill was the most intense feeling of joy and exhilaration and ugly tears for many, many, many minutes."
Sidler spends the time she gained back as a heart health advocate. Her message for others - look for the signs.
"Take care of yourself first, check in on the people who you love, and make sure that they're taking care of themselves, because blood pressure is a silent killer.
"We oftentimes don't know we have these symptoms until it's too late. So let's get ahead of it, let's be preventive."
That's why knowning your numbers is so important. You might feel okay might you want to make sure your heart isn't working too hard.
Kristy is committed to sharing her story and fighting heart disease - she's an author and the chair for the Circle of Red – The American Heart Association's society that helps fight heart disease and stroke.
As the American Heart Association turns 100 it's looking to share 100 survivor stories.
If you want to share your story, email 100survivors@heart.org.
Kristy Sidler