Vice President Richard B. Cheney's heart condition may adversely affect his job performance, said professors from the Harvard Medical School (HMS) and Kennedy School of Government.

Cheney, 60, recently released after being hospitalized for heart trouble, has a history of coronary disease.

He suffered the first of four heart attacks at age 37 and experienced his most recent in November, when a mild attack briefly sidelined Cheney during the dispute following the presidential election.

And on Monday, Cheney checked into George Washington University Hospital reporting chest pains.

Doctors found that scar tissue had developed around the artery support structure, known as a stent, used in the November angioplasty, and blockage in the artery had returned to 90 percent of its original severity.

Eugene Braunwald, a professor at HMS, said the problem could return.

"This [latest incident has] about a 40 percent chance of declaring itself again," Braunwald said.

And Braunwald said the severity of Monday's problem has been downplayed by the White House.

"Legally, I agree [with Cheney aide Mary Matalin] that it was not an emergency procedure. On the other hand, the procedure was urgent," he said.

Braunwald said that despite Monday's operation, the risk of problems in other areas of Cheney's circulatory system still persists.

"[Cheney] is at a modest risk of developing a de novo problem in his coronary tree in a region that wasn't stented," Braunwald said.

Because of the prospect of future heart problems, some have questioned whether Cheney should serve as vice president.

The concerns are particularly relevant for Cheney, said Bradlee Professor of Government Thomas E. Patterson, because of Cheney's elevated role in President George W. Bush's administration.

"There are some unusual circumstances with this particular presidency and vice presidency," Patterson said. "Bush is one of the presidents with the least experience. Cheney, on other hand, is one of the most experienced vice presidents."

Though Cheney has taken on more responsibility, Braunwald said stress alone was not behind Monday's incident.

"His diet and lost weight are more important than the stress of his job," Braunwald said, although he said that Cheney's efforts to live well, like eating more vegetables and not smoking, have led his overall health to improve.

But Cheney's elevated role in the Bush administration may still put him at extra risk.

"Cheney will require more care than somebody without coronary disease," Braunwald said, especially "if he flew to a nation that didn't have a good hospital system."

Patterson said he is less concerned about these kinds of scenarios, given what he says is the usual role of a vice president.

"The importance of being a foreign ambassador is somewhat low," he said. "That role can be carried by the secretary of state."

Cheney's heart condition also raises questions regarding how much information elected officials should reveal to the public, as Cheney has so far refused to make his medical history public.

Braunwald and Patterson both said that some amount of public disclosure is appropriate and inevitable for public servants.

"If you're going to be in a major role like this, you're in a goldfish bowl," Braunwald said.

Patterson said he feels that, to a point, the scrutiny of Cheney is warranted.

"The release of the kinds of things that are relevant to his position--that should be made public," he said.