NASHUA, N.H. (CNN) Barry Maden is a self-described tech geek. It's part of why he wanted to buy himself an Apple Watch.
He also keeps a close eye on his health after suffering from a brain injury.
"He originally got it because they have a new fall risk app, right? Where if he were to fall and I'm not nearby, the fall sensor will sense that he fell and call 911," wife Tara said.
But in this case, it actually ended up detecting something that Barry didn't even have on his radar.
"And it said it looks like your heart is in AFib, you should contact your doctor," Barry said.
AFib or atrial fibrillation is an irregular heartbeat that if left untreated-- or in Barry's case undetected-- could lead to blood clots, causing a stroke or other heart complications.
The watch showed Barry what his actual heartbeat looked like. He finally decided to go to the hospital.
"When I got to the ER, they did an actual EKG on a cart, with the real deal," he said.
Sure enough, the medical professionals told Barry the same thing: he was in AFib.
"It probably would have taken me longer to get to the doctor's had I not had something actually telling me that something's not right," Barry said.
He was sedated and his heart was essentially stopped and restarted by doctors.
Now, this small piece of technology suddenly seems like so much more to the Madens.
"Instead of being just kind of a toy or a tchotchke, I think I'll probably pay more attention to it," Barry said.
"Just grateful," Tara said. "Blessed."
The electrocardiogram feature on the Apple Watch does have limitations. It can't detect most heart rhythm abnormalities or electrical changes associated with a heart attack.