Posted Sunday, July 29, 2:30 p.m.

Surgeons at GW Hospital successfully replaced the battery and generator in Vice President Dick Cheney’s implanted defibrillator, a device used to monitor his heart rhythms, said Megan McGinn, the vice president’s deputy press secretary.

“The device was successfully replaced without complication,” McGinn said.

The vice president arrived at the hospital early Saturday morning with his wife Lynne, left at approximately noon and returned to his home at the Naval Observatory, McGinn said.

Cheney, 66, has a long history of heart disease and successful treatment. He has had four heart attacks, quadruple bypass surgery, two artery-clearing angioplasties and an operation to implant the defibrillator, according to the Associated Press.

The implanted defibrillator operates by monitoring Cheney’s heart rhythms and delivering an electric shock to the heart if and when the device records an irregular rhythm.

Cheney and his doctors realized the battery and generator in the implanted defibrillator needed replacement during Cheney’s annual physical last month.