John McCain's campaign has suffered a Heart attack -- of the legal variety.

TMZ.com is reporting that Ann and Nancy Wilson are upset that their 1977 rock hit "Barracuda" was used without their permission in the Xcel Energy Center at the Republican National Convention in St. Paul.

The Heart duo has "fired off a cease and desist letter" to the McCain/Palin campaign, the gossip website is reporting this morning.

Specifically, TMZ.com says, Heart is upset that the GOP is using "Barracuda" as a theme song for veep candidate Sarah Palin. Her "Sarah Barracuda" nickname dates back to her high school basketball days as praise for her intensity on the court.

TMZ.com says it obtained a statement from Heart's rep, who says, "The Republican campaign did not ask for permission to use the song, nor would they have been granted that permission."

The statement goes on: "We have asked the Republican campaign publicly not to use our music. We hope our wishes will be honored."

-- PAUL WALSH