Demi Lovato's 'Heart Attack' Single Causes Palpitations: Listen

Demi Lovato's new single "Heart Attack" has hit the Web one week before it was due to premiere on Ryan Seacrest's syndicated radio show. On Sunday night (Feb. 24), after two weeks of teaser snippets were posted online, the sweeping electro-pop track leaked in full, previewing the former Disney star's forthcoming fourth album.

Lovato's 2011 album "Unbroken" was led by the somber ballad "Skyscraper," but "Heart Attack" whirs into motion with the same intensity as the 20-year-old's breakout hit "Give Your Heart a Break." Produced by the Suspex, "Heart Attack's" hook rests upon a breathy guitar lick that lead directly into a monstrous percussion breakdown, and Lovato is in full, Clarkson-esque belting mode as she declares that she's "putting my defenses up/'Cuz I don't wanna fall in love."

Earlier this month, Lovato released a teaser of the song, and shared that her still-untitled next album will be more personally revealing. "For a while, I could tell that, when people would talk to me, they knew my story," she said. ""I think I've opened up more on this album. My life began to evolve, and I started to grow."

"Heart Attack" is now available on iTunes, and the follow-up to "Unbroken" is expected to arrive later this spring. Lovato still has not confirmed her involvement on the next season of Fox's "The X Factor," which she joined as a judge last fall.