Heart diseaseis the leading cause of death in the U.S. After that I dont remember anything until waking up in the hospital.

Her friend told her later that it looked like she bent over to tie her shoe.

But when she realized Elfering had collapsed, she called for help.

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Elfering (left) with her friend before the 2018 New York City Marathon.

Elfering doesn’t remember there being any other clues that something was going to happen ahead of time.

I only remember thinking that our pace had slowed down, she says.

I left feeling great and was even out at museums and seeing other tourist attractions, she says.

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Elfering during a 100-mile ultramarathon trail race

But days later, in the car, she had a second cardiac event.

The defibrillator saved my life for a second time, she says.

The portable defibrillator shocked me a number of times and kept my heart going until the ambulance came.

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Elfering competing in a triathlon

She was taken to the hospital again, where she stayed for nine days.

If a coronary artery is completely blocked, a heart attack can occur.

(Elfering learned she had a complete blockage in a lower artery after her heart attack.)

Having a family history of heart diseaseincreases your risk of developing it.

Elfering also isnt allowed to drive, so she has to rely on family and friends to get places.

I have gone from being a very independent person to someone that is dependent on others, she says.

Everyone is happy to help and support me, but I am not used to being in that position.

I always thought it potentially could be an issue for me, but never imagined at this age.

She also hopes that her story inspires people to get certified inCPR.