Vice President Cheney got good news yesterday during his annual heart checkup, with a pacemaker detecting no irregular heartbeat, his office said.

Cheney has had four heart attacks, and a pacemaker was placed in his chest in June 2001. The checkup determined that the pacemaker, called an implantable cardioverter defibrillator, was working fine and has never had to be activated. The device is designed to activate automatically if needed to regulate the patient's heartbeat.

Cheney underwent the routine exam at George Washington University Medical Center. It included a physical exam, an electrocardiogram, an echocardiogram and a stress test -- all noninvasive procedures. The vice president went back to work afterward.

"The vice president's cardiac status remains stable, his [implantable cardioverter defibrillator] neither detected nor treated any arrhythmia, his exercise capacity continues to be excellent, and his stress test is unchanged," said Cheney spokeswoman Jennifer Mayfield.

Cheney will have a colonoscopy and a screening test for vascular disease later this month.

In the afternoon, the vice president went to the British ambassador's residence, located next to Cheney's home in the Naval Observatory compound, and signed a condolence book for the victims of the deadly rush-hour bus and subway bombings in London.

Vice President Cheney returns to work after a routine examination.