Demi Lovato suffered an embarrassing moment of lapsed concentration on live national TV as she messed up lyrics.

The talented singer was performing her latest single 'Heart Attack' on Good Morning America on Wednesday (April 10) when the slip happened.

It was all going well until the X Factor USA judge began to sing the song's second verse instead of the first.

However, she managed to maintain her composure and revert back to the correct lyrics half way through the verse, before repeating the second.

Like a true pro, Lovato managed to get through the blip with a knowing smile before finishing the track with aplomb.

'Heart Attack' is the lead single from the singer's forthcoming new album 'DEMI', which is released on May 14.