The stress American University's basketball players were undoubtedly feeling as their game with Georgetown Wednesday night turned into one of the season's biggest upsets was reflected by their coach, whose heart was being monitored by the Washington Cardiovascular Institute during the game.

AU Coach Ed Tapscott's pulse rate reached 170 beats a minute -- more than double the normal rate of a sedentary individual -- during critical moments of AU's upset, according to a taped electrocardiogram arranged by doctors at the Washington Cardiovascular Institute.

At 7:45 p.m. Wednesday -- 22 minutes before tipoff -- Tapscott was fitted with a portable monitoring device about the size of a package of cigarettes, which was hung around his neck and tucked under his shirt. Electrodes were attached to his chest and connected to the monitor so that a complete tape recording could be made of his heart's activity during the game, in which AU defeated the fifth-ranked Hoyas, 62-61.

"We know that coaching is a high-risk activity from a cardiovascular point of view," said a physician at the Institute, who said he preferred not to be quoted by name. The institute has also done on-the-job cardiovascular stress tests of such high-pressure occupations as firefighting and police work.

Heartbeat rate is one symptom of stress, but is not in itself indicative of a dangerous situation.

According to the cardiologists, the electrocardiogram showed no irregularities in Tapscott's heart activity, and at his age -- 28 -- and with his normal physical condition, there is no cause for concern about his being subjected to such stress.

But in an older and less healthy man such stress might well bring on a heart attack, the physicians said. Last Saturday, South Carolina Coach Bill Foster suffered a coronary and later underwent quadruple bypass surgery.

Tapscott said doctors at the Cardiovascular Institute suggested his heart be monitored during the game after he had taken one of his players there for examination of a high blood pressure condition.

Tapscott said he discussed undergoing a stress test with the physicians and that they said during a game would be the best time, since that was when he was under greatest stress. "It seemed like a good idea," said Tapscott. "We might try it again at another game. I guess I was as nervous about that game as about any."

The players were warming up when AU's head trainer, Dave Tomkalski, attached the monitoring device. At that point, the coach's heart was beating at the rate of about 75 beats a minute, slightly above normal but considered within the normal range.

By tipoff, the rate had risen to 118 beats a minute, and at 8:14 -- seven minutes into the game -- it had risen to 140. According to Tomkalski, this coincided with what Tapscott considered to be a referee's bad call.

The high stress point came at 9:13 p.m., just as Georgetown was beginning to overcome what had been a substantial lead by AU, and Tapscott was striding up and down the sideline shouting at his players. This was also the point at which Georgetown center Patrick Ewing was called for his fourth foul. Tapscott's heart was beating at the rate of 170 beats a minute.

Within a few minutes, Tapscott sat down on the bench, and his heartbeat slowed to 130 a minute, still about double the normal rate. It stayed in that vicinity until the end of the game.