Former U.S. vice president Dick Cheney says he once thought jihadists could send a signal to his heart defibrillator, so he had his doctor adjust the device to disable its wireless function.

In a 60 Minutes interview airing Sunday, he said he found the threat of an assassination attempt credible.

Cheney had a defibrillator implanted near his heart in 2007 to detect irregular heartbeats and control them with electrical jolts.

He has a history of heart trouble, suffering the first of five heart attacks at age 37. Cheney underwent a heart transplant last year at age 71.

He told the CBS show that he and his doctor, cardiologist Jonathan Reiner, turned off the device's wireless function in case someone tried to send his heart a fatal shock.

Years later, Cheney watched an episode of the Showtime series Homeland in which such a scenario was part of the plot.

"I was aware of the danger, if you will, that existed, but I found it credible," Cheney told 60 Minutes. "Because I know from the experience we had and the necessity for adjusting my own device that it was an accurate portrayal of what was possible."