Demi Lovato Rescued 'Heart Attack' And Brought It 'To Life'

While Demi Lovato's latest single "Heart Attack" sounds like it was tailor-made for the big-voiced singer, you might be surprised to learn that the "X Factor" mentor was hardly the first diva interested in the bouncy track.

Jason Evigan, one half of the song's production team The SUSPEX, reveals once Lovato got her hands on it, she made it all her own.

"The first version had a dub step break in it. We took that out for her ... Demi has magic to it where she has so much sass in her voice but yet so much power and all those really high notes at the end, she added that on the spot," he told about the lead single off her May 14 album, Demi. "[Some of those notes are] all freestyle and like that, I feel like, took the song up notches."

The song was originally intended for singer Nikki Williams. She, along with Evigan, and his team (including co-producer Mitch Allan as well as songwriter Sean Douglas) dreamed up the track after she came into the studio talking about one of her crushes several years back.

"I pulled the title 'Heart Attack' from when [Nikki] actually likes someone, she has a heart attack," Evigan recalled. But when they brought it to the record label "they actually didn't want it. And we thought 'Wow that's surprising.' We thought it was going to be a hit."

Next up, former "American Idol" contestant Pia Toscana was interested in the song, but her recording hardly surfaced. So the song sat around, until Demi came along.

Evigan explained, "A lot of people wanted the song. And then Demi came in to do another song called 'Two Pieces' and then we played her 'Heart Attack' and she freaked out about it. So she came in to record it and then she actually had a couple of lyric changes that were really good. She added that super high note at the end and she added some really cool things to it and she brought that song to life. Now it's taking off."

While the track has gone through a number of changes over the last couple years, he says that as it stands now "it's funny because when you strip the song down, stand alone, I think it's a really classic song."

With so many female pop stars angling for the next big club track, Evigan says that Lovato is more focused on creating songs that will define her legacy, not just her current incarnation. "She's one who is so not about just trying to be what's on radio. She's a total original soul, she just wants to make what moves her," he said. "And if it moves her she loves it. She's all about if the song moves her. She's all about going harder, which is cool."

For fans hankering to see why Demi had her hands painted black recently, the Chris Applebaum-directed video for "Heart Attack" will premiere on E! News on April 9 at 7 p.m. ET.