In one incident, the 65-year-old man who had suffered three heart attacks, collapsed while watching television with his son and could not be aroused. The son, who had not been trained in CPR, tried compressing his father's chest, but the effort was unsuccessful. The father remained breathless and without a pulse.

The son then remembered that his mother had resuscitated her husband six months earlier with a toilet plunger. He found a plunger and applied suction to his father's chest for 10 minutes until paramedics arrived.

By then the father had begun breathing and moving on his own. He was brought to San Francisco General Hospital, where he recovered. Hospital officials, who did not name the family, said yesterday that they did not know whether the father was still in good health, or what had inspired his wife to try the plunger in the first place.

But the son, delighted with his success, suggested that doctors place toilet plungers next to all the beds in the coronary care unit.

Though most doctors found the story amusing, Dr. Keith G. Lurie and his colleagues took it seriously. They speculated that the plunger led to improved circulation and also served to ventilate the patient.

The doctors began experiments on dogs. Dr. Lurie and two colleagues also described their work -- and the desperate actions that inspired it -- in a letter published in 1990 in The Journal of the American Medical Association after it was rejected by The New England Journal of Medicine.

The dog studies showed that standard measures like heart output, pressure in the heart's main artery, the amount of blood circulating in the coronary arteries that feed the heart, and breathing were significantly increased with the plunger technique as compared with the standard method.