Women typically take an hour longer to get to the hospital when they have a heart attack and are treated less urgently once they arrive, explaining in part why they are more likely to die.

Doctors have long noticed that heart attacks are more likely to be fatal in women than in men, but they have had trouble sorting out how much of this could be explained solely by the severity of their illnesses.Two large new studies suggest that women's worse medical conditions clearly do play a big part.

However, the researchers also found small but clear differences between the sexes in the way both doctors and victims react to heart attacks, which are the No. 1 killer of men and women alike.

One reason women take longer to get to the hospital is that they are less likely than men to suffer crushing chest pain, the hallmark sign of a heart attack. Instead, they may have more ambiguous symptoms, such as shortness of breath, an ache in the neck or jaw or something that feels like gas pains.

One of the researchers, Dr. Sandra Gan of Swedish Medical Center in Seattle, also speculated that doctors may treat women less aggressively simply because they tend to be older and sicker. And she said non-heart specialists, in particular, may be less likely to recognize and treat heart attacks in women.

The findings, based on large national databases, were presented Wednesday at a meeting in Atlanta of the American College of Cardiology.

Gan described an analysis of gender differences in the care of 180,083 elderly Medicare patients in 1994 and 1995, and Dr. John Canto of the University of Alabama in Birmingham outlined findings from 327,040 men and women of all ages treated at about 1,500 U.S. hospitals from 1994 to 1996.

The data show that women are almost 50 percent more likely to die from their heart attacks than are men. Much of this can be explained by women's older age and worse health. They are typically about 10 years older than men when they have heart attacks. They are more likely to have other complicating diseases, such as diabetes and high blood pressure. And the small size of their coronary arteries makes them more difficult to treat with some procedures.

Still, both studies showed that when age and other medical differences were taken into consideration, women were still 13 percent more likely than men to die of their heart attacks.

One of the biggest differences was the urgency with which women get to the hospital. Canto found that women are less likely than men to call an ambulance, and on average they arrive at the hospital 6.2 hours after their symptoms start, compared with 5.3 hours for men.