Heart Attack by Demi Lovato is in Bbm at 85 beats per minute and runs 3:12 across 46 bars. It uses 8 chords — Db, Cm, Fm, N.C., Ab, Eb, C7, Bbm. The chord diagram changes as the song plays and the words light up as they are sung, so you can strum and sing along without reading ahead.
Want the melody line note by note? Heart Attack guitar melody tab.