Paramedics recorded Mayor Marion Barry's blood pressure at 238 over 144 -- far above a normal rate -- in the minutes after he inhaled crack cocaine and was arrested by agents bursting into his hotel room, according to a transcript of the Vista videotape made by the government.

At that moment, some medical experts say, Barry was a candidate for a stroke or heart attack and should have been taken to a hospital. He was not. One doctor, however, said Barry probably was not in danger.

U.S. District Judge Thomas Penfield Jackson already has ruled that the government acted properly when it allowed Barry to twice inhale crack from a pipe after he had sipped cognac with a former girfriend, Hazel Diane "Rasheeda" Moore.

Barry has said, however, that prosecutors tried to "kill" him. And several physicians said they would never have sanctioned an undercover operation in which the target was allowed to smoke cocaine. Cocaine stimulates the heart and constricts arteries, elevating blood pressure.

"I personally could not advise a police officer to give that stuff to somebody," said Paul Grayburn, a cardiologist at the Veterans Administration hospital in Dallas who has researched the effects of crack and cocaine. "I could not advise anyone to take a drug I know could kill them."

Barry's blood pressure was so far above a normal rate of 120 over 80 that "in most cases, that would be an automatic badge of {hospital} admission or at least a trip to the emergency room," said Jeffrey Isner, a professor of medicine at Tufts University and a recognized expert on the effects of cocaine.

However, Robert L. DuPont, a physician who is a former director of the National Institute On Drug Abuse, said that "99 out of 100" people whose blood pressure suddenly rose that high would face no immediate danger because the body can sustain pressures much higher. While the cocaine fueled the reading, he said, the stress of his arrest probably was a factor.

DuPont also said that Barry's high reading suggested "he has a tendency toward high blood pressure anyhow."

On the videotape released yesterday, federal agents and D.C. police officers repeatedly asked Barry about his condition, and he repeatedly replied that he felt all right. They promised he would be examined by emergency medical technicians but it was several minutes before that was done.

The transcript shows that Barry was not told he was at risk or that his blood pressure was high. A paramedic did say the crack "could be adverse" to the mayor's health. And paramedics checked his respiration and other vital signs, asking Barry if he was on any medication or had allergies, chest pains or any discomfort.

At one point, an officer told Barry, "We know about your past cardiac history with narcotics." His meaning wasn't clear.

In 1983, Barry was admitted to Howard University Hospital after complaining of chest pains and breathing difficulties. In 1987, he was briefly hospitalized in Los Angeles. In both cases, his problem was diagnosed as a hiatal hernia, whose symptoms can mimic cardiac problems.

Barry was asked if he wanted to go to a hospital, according to the transcript, and said no. "I'm going to take a chance," he said.

U.S. Attorney Jay B. Stephens has defended the undercover sting operation, saying that medical personnel were on hand to treat Barry if he had a reaction. In any event, Stephens said in court papers, Barry had ingested crack and cocaine on numerous occasions. Moore testified yesterday, however, that at the time of the sting the government was unaware that Barry had once nearly collapsed after smoking crack with her.

Medical experts said a serious reaction to crack could have defied treatment at the time of the sting. A stroke could occur with no more warning than Barry's high blood pressure, physicians said, and the drug can interfere with normal heart rhythm and prevent resuscitation.

Doctors added that Barry's alleged past use of cocaine -- and his ability to tolerate it -- would be no reason to believe he would not be at risk. "Crack can kill the first time you smoke it or the 10,000th time," said Grayburn.

Even young people with normal hearts have had fatal heart attacks after smoking crack, Isner said. The chances of problems could be higher, he said, in people like Barry who are over 50 and more likely to have some coronary disease. "There is no question that cocaine can provoke spasms in the coronary arteries that can in turn cause a heart attack," Isner said.

Sources said yesterday that D.C. Police Chief Isaac Fulwood Jr. was aware of the prosecutor's plan to allow Barry to use cocaine and disapproved on medical grounds.

Stephens has not commented publicly on why the government did not arrest Barry as soon as Moore gave him cocaine but before he used it. Under federal law, there is no distinction between possessing an illegal drug and using it; they carry the same penalty.

But Greta Van Susteren, a defense attorney, said if agents had burst in before Barry had smoked the cocaine, "the jury might have thought he didn't truly possess it."

Asked about the health risks, she added, "Doctors are in the business of keeping people healthy and alive, and Jay Stephens is in the business of putting people in jail."

Paul Rothstein, a Georgetown law professor who attended yesterday's session of the Barry trial, said that if the mayor had been arrested simply holding the crack pipe, he could have argued that "someone slapped something in his hand" and that he had no idea what it was.

"And so they {the prosecutors} have to convince the jury in a dramatic way that he's a user," Rothstein said. But he added the jury might be offended by the medical risks involved in the sting.