DALLAS, Nov. 14 - Some heart attacks are sudden and intensely painful, but most start slowly, with mild pain or discomfort that lasts just a few minutes. As a result, people often wait hours to seek help, a delay that can be lethal.

But researchers reported here Monday that there is one symptom that apparently causes people to seek help more quickly: sweating.

For many years, doctors and health officials have urged people who experience the common symptoms of a heart attack - pain or discomfort in the chest, arm, neck or jaw, sometimes accompanied by shortness of breath, a cold sweat, nausea and lightheadedness - to seek help immediately.

Despite such efforts, the time it takes people to seek care has not shortened significantly and delays remain a serious problem. So doctors led by Catherine J. Ryan of the University of Illinois at Chicago undertook a statistical study to determine whether the kind of symptoms determined the length of delay.

Dr. Ryan found that people who sweat as part of their cluster of symptoms delayed the least amount of time in seeking help, while those with minimal or no sweating called for help later. The researchers, who reported their findings at the annual meeting of the American Heart Association, did not specify a precise difference.

Dr. Ryan said in an interview that earlier studies about delays focused on one symptom, not clusters. So she asked the authors of 10 such studies to send their data, under a recent policy from the National Institutes of Health that allows one team of researchers to use data collected by others.

Eight groups of authors in the United States and Britain cooperated. These researchers had collected their data in interviews with 1,073 patients who had experienced heart attacks.

Dr. Ryan studied 12 common symptoms: chest discomfort; shoulder, arm, or hand discomfort; neck or jaw discomfort; back discomfort; abdominal discomfort; indigestion; nausea and vomiting; shortness of breath; sweating; dizziness and light-headedness; weakness; and fatigue.

According to her analysis, using standard statistical techniques, people with the shortest delay time, a mean of 9.78 hours, had a greater probability of experiencing the largest number of symptoms. People with the longest delay time, a mean of 22.77 hours, had a moderate probability of experiencing chest pain and shortness of breath. Sweating emerged as an important factor, Dr. Ryan said.

The research could not determine whether sweating was an indication of a more serious heart attack.

Emphasizing that definitive conclusions cannot be drawn from one study, Dr. Ryan said the results should encourage other scientists to confirm and extend the findings in further research intended to find better ways to reduce the delays.