A pacemaker device was implanted in Vice President Dick Cheney on Saturday to guard against bouts of dangerously rapid heartbeats, a preventive measure doctors likened to "having a cardiologist in your chest 24 hours a day."
Physicians at George Washington University Medical Center, where the hourlong procedure was performed, emerged in their hospital scrubs to pronounce Cheney's prognosis "terrific" and his life expectancy "excellent."
Cheney walked out of the medical center about 3 p.m., seven hours after he checked in. He waved to well-wishers and held hands with his wife, Lynne. "I feel good," he said before climbing into his limousine. "Sore shoulder."
It was the third time since the November election that Cheney has been hospitalized for cardiac problems. On Saturday, doctors emphasized that the device was implanted "not to react to a crisis, but to prevent a crisis" and said that the 60-year-old vice president could return to work Monday without restrictions, which Cheney planned to do.
"He is the same person that he was on Friday, with the addition of this electronic insurance policy under his skin," said Dr. Jonathan Samuel Reiner, Cheney's cardiologist.
Still, doctors acknowledged that Cheney's overall heart function remains diminished, the result of four heart attacks since 1978.
Reiner said the volume of blood pumped from Cheney's heart with each beat is below normal, operating at a level of "moderate impairment."
For his part, Cheney appeared to glide effortlessly through Saturday's ordeal. Sedated during the procedure, he opened his eyes immediately afterward and asked what time it was, ate a shrimp salad for lunch and took only Tylenol for pain, his doctors said.
Among White House officials, every effort was made to stress that Cheney is capable of continuing his duties as vice president, despite his medical problems.
At Camp David in Maryland, Bush took time out from a meeting with Japanese Prime Minister Junichiro Koizumi to call Cheney in the hospital recovery room.
During a photo session later, Bush said he does not expect his vice president to slow down.
"I know he ought to work at a pace he is comfortable with. And I know Dick Cheney well, and if I were to say, 'You've got to slow down, Mr. Vice President,' he's going to say, 'Forget it,' because he's got a job to do, and he's a valuable member of my administration. And I look forward to seeing him in the Oval Office Monday morning."
Cheney elected to go forward with the implant after a monitoring device strapped to his chest for 34 hours recently detected four episodes of a rapid heartbeat lasting a total of about five seconds.
In a worst-case scenario, such irregular palpitations could cause a sudden stoppage of the heart and death.
Saturday's procedure was two-part. The first, a 35-minute diagnostic test in which doctors were able to induce a quickened heart rate, convincing them that the vice president was susceptible to the life-threatening malady known as arrhythmia.
The second part involved the implantation of the "pacemaker-plus" that monitors every heartbeat and records them in a computer's memory. Two devices in one, the pacemaker kicks in if the heartbeat slows down, and a defibrillator triggers if the heartbeat speeds up, correcting it with an electrical current.
The implantable cardioverter defibrillator (ICD) was placed just under the skin of Cheney's left shoulder. Fine wires were threaded from the pager-size device into veins that lead to the heart. Inside the heart, one wire used for pacing was placed in the upper chamber and the other wire, which includes a defibrillator coil, was placed near the edge of the lower chamber.
Doctors said that, except for a small bulge on his chest and a propensity to set off airport metal detectors, Cheney will hardly know the device is there--adding that it may never be required to activate.
The only restriction doctors imposed was that Cheney must stop vigorous upper-body exercise until the implant scars over and sets in place. He also was instructed that any use of a cell phone must be on his right side to avoid disrupting the proper function of the electronic device. Otherwise, doctors encouraged him to resume his regimen of lower-body aerobic exercise four times a week.
Other physicians not directly involved with the vice president's care said Cheney's heart disease would restrict him from physical labor but should not interfere with the demands of an executive.
"He won't be running a four-minute mile, but he can take good walks without any symptoms," said Dr. Raymond L. Woosley of Georgetown University Medical Center, an expert in the implant procedure. "I think the odds are that he's going to continue to have some problems. But I think they're not going to interfere with his ability to finish a successful [four-year] term as vice president."
Dr. Douglas Zipes, president of the American College of Cardiology in Indianapolis, who has consulted with Cheney's cardiologist, during the last two weeks, was even more optimistic, calling Cheney's prognosis "superb."
"He really should be in excellent shape at this point," Zipes said. "I see no reason that he can't continue for, certainly, the remainder of this administration and possibly a second."
Still, Cheney's heart is damaged, as doctors detailed Saturday. The volume of blood displaced with each beat--characterized by his doctors at 40%--is well below the normal "ejection fraction" range of about 55% to 70% found in a person with a healthy heart.
The image of Cheney leaving the hospital served as a public reminder that the vice president has a history of serious health problems. It is bound to stir questions whether his large role in the Bush administration--as top advisor on foreign affairs, chief lobbyist on Capitol Hill and energy policy point man--exceeds his physical limits.
"I don't hear any clamor in either party for him to step down," said Charles Cook, an independent Washington political analyst. "How much his performance will be restricted in the future by his health we have no idea. But I think the job is his as long as he can continue to carry it out and it's not a danger to him."
Cheney underwent quadruple bypass surgery in 1988 to clear clogged arteries after his third heart attack. He went on to serve as Defense secretary during the administration of Bush's father and then to carve out a career in the oil business before being tapped as the GOP vice presidential candidate.
The fourth mild heart attack came during the Florida presidential election turmoil in November. Then doctors inserted a mesh tube to keep open an artery. When he complained of chest pains, Reiner performed a procedure, called an angioplasty, on March 5.
"I don't really put much stake in the number of admissions to the hospital," Reiner said. "I would focus on how he is able to perform."
But Zipes acknowledged that the November heart attack, the blockage found afterward and the newly diagnosed heart-rhythm abnormality raise concern.
He explained that Cheney is at risk for two problems: a clogged artery and abnormal heart rhythm, and only the latter is expected to be neutralized by the implant.
While Cheney has said that he would resign if his health interfered with his duties, less has been said about what his expansive duties might be doing to his health. On Saturday, his doctor minimized the role stress might play.
"Most people who know the vice president don't find him to be a particularly stressed person," Reiner said. "It's really hard to pin stress on this problem."
And, as Zipes noted, staying on the job could be the less-wearing path for a career politician.
"It could be even more stressful not to do it than to do it."
Times staff writer Edwin Chen contributed to this story.