Demi Lovato’s new single, “Heart Attack,” went live on iTunes on February 24 in over 45 countries around the globe, and is No. 1 on iTunes in 14 of those territories, including the US, Argentina, Brazil, Chile, Costa Rica, Dominican Republic, Venezuela and Singapore. “Heart Attack” made its radio debut last week on KIIS FM, with an exclusive interview with Ryan Seacrest. “Heart Attack” is from Demi Lovato’s forthcoming June album. Shortly after the release of “Heart Attack” on iTunes, Demi caused seven worldwide Twitter Trends.