PHOENIX — A 13-year-old Valley boy says his smartwatch saved his life.

"I started feeling light-headed and I looked down at my heart rate and it said 219."

Lynsey Hardison, Austin's mother, remembers that early August day and admits she was a little skeptical when her son told her his smartwatch said his heart rate was almost 220 beats per minute (bpm).

"I knew school was starting next week and he was getting a little anxious for that and I thought maybe it's just anxiety."

According to the Centers for Disease Control and Prevention, your maximum heart rate is 220 bpm, minus your age. The American Heart Association says for most of us, our normal resting heart rate should be around 60 to 100 bpm.

So for Austin, his maximum heart rate should've only ever been 207 bpm. He should've only been able to reach 220 bpm under extreme circumstances like if he had been doing vigorous physical activity - not sitting on the couch watching TV like he was when his smartwatch alerted him.

The Hardison's fearing something was very wrong, took Austin to Phoenix Children's and found out: "He had a heart condition called Wolff-Parkinson-White Syndrome and he was actually born with it and just we were never aware of it," said Austin's mother.

Crediting the discovery to that smartwatch, Austin wanted as a Christmas gift nearly a year ago. A watch Austin now knows can do more than just show YouTube and play games.