For Russian doctors talking about the medical problems of a Russian leader, it was an unprecedented display of candor. For 45 minutes last week the physicians treating Boris Yeltsin gathered at a press conference in Moscow to answer questions about the world's most closely watched--and until now, closely guarded--heart condition.

The news could have been a lot worse. The doctors confirmed that Yeltsin has four constricted coronary arteries--including one that is effectively blocked--and needs bypass surgery. They described several recent attacks of angina. The doctors even admitted that there have been "complications" involving his lungs, liver and kidneys after a heart attack in June--although they stopped short of confirming widespread speculation that his liver is severely damaged from a life of heavy drinking. All things considered, his body is in pretty good shape. After another six to 10 weeks of enforced rest at the hospital, the doctors declared, Yeltsin would have close to a 100% chance of surviving heart surgery.

Yet there was enough ambiguity in the official remarks to raise eyebrows among cardiac surgeons around the world. And to raise questions about whether the Russian leader is getting the best possible care--or even care comparable to that which ordinary citizens get every day in Europe and the U.S.

If Yeltsin were really as strong as his doctors say he is, several American heart specialists suggest, then there is no reason to postpone surgery. In fact, they believe his chances of suffering another, more destructive heart attack will only increase the longer Yeltsin goes without treatment. "I don't understand quite what the rationale is for waiting," says Dr. Sidney Levitsky, chief of cardiothoracic surgery at New England Deaconess Hospital in Boston. "My inclination would be to do the bypass early, not late, since he is now sitting on the razor's edge."

Adding to the drama in Moscow was the presence of Dr. Michael DeBakey, the world-renowned heart specialist who trained the head of Yeltsin's surgical team and who was asked by the White House to consult on the Russian leader's condition. After examining Yeltsin, DeBakey seconded the Russian doctors' positive assessment and treatment plan. He also tried to lay to rest several rumors. No, he told the New York Times, President Yeltsin has not suffered a stroke. No, there is no heart damage beyond the constricted sections of his coronary arteries. No, he has not been taking steroids.

DeBakey considers the operating delay prudent because he thinks the physicians should pinpoint the source of a bout of internal bleeding that Yeltsin suffered last month. The most likely culprit: the aspirin his doctors prescribed after his June attack. Now that he is no longer taking aspirin, the hemorrhaging has stopped. If the bleeding were to recur during the operation, however, it could prove fatal. Better to correct the President's anemia with blood transfusions and make sure the bleeding doesn't start again.

The explanation seems reasonable enough, but even this puzzled some U.S. experts. "We operate on anemic patients with unstable angina all the time," says Dr. Timothy Gardner, chief of cardiac surgery at the Hospital of the University of Pennsylvania. "We can make the correction for anemia at the time of surgery." The only reason Gardner could see for delaying the bypass would be if Yeltsin had significant bleeding from an unhealed ulcer. Even then, Gardner would expect it to take only two to three weeks to mend, certainly not six to 10.

Yeltsin's doctors may be erring on the side of caution. Bypass surgery is not, after all, that common in Russia. In the U.S., by contrast, it often seems like just another rite of passage. American doctors perform almost 9,000 such operations each week--three times the number performed in Russia in an entire year. So it comes as no surprise that U.S. cardiac surgeons would recommend aggressive treatment.

Which brings up a final puzzle: Why is Boris Yeltsin being operated on in Russia at all? Even some Russian doctors last week were urging that their leader be transferred to a European or American hospital--where surgeons have become so skilled at bypass operations that patients are discharged from the hospital in about a week, vs. two months in Russia. "We have only one President," says Dr. Alexander Grinberg, professor of surgery at the Russian State Medical University. "[Yeltsin] should be operated on in the West for the same reason that Aeroflot bought Boeings."

--Reported by Alice Park/New York and Paul Quinn-Judge/Moscow