US Vice-President Dick Cheney has had minor surgery to replace the battery that powers his heart pacemaker.
Dick Cheney has a long history of heart trouble
Doctors discovered last month during a routine physical check that the pacemaker's battery was running low.
The pacemaker, called an implanted cardioverter defibrillator, monitors and maintains Mr Cheney's heartbeat.
Mr Cheney, 66, has had four heart attacks, quadruple bypass surgery and operations to clear blocked arteries. He was fitted with a pacemaker in 2001.
He has also had operations to clear blood clots in his knees and in March started taking blood-thinning medicine to treat another blood clot in his lower left leg.
The operation to replace his pacemaker battery was carried out at George Washington University Hospital in Washington.
During his June physical check-up, doctors said the pacemaker had been functioning properly and that the vice-president showed no signs of new coronary blockages.