Americans who live in the South are more likely to die from heart disease than those who live west of the Mississippi River, a report said.

The 1991 edition of the American Heart Association's Heart and Stroke Facts showed Sunday that there is considerable geographical variation in the risk of dying from the nation's No. 1 killer in the United States."These trends have persisted for quite a while, and they probably reflect the infuences of lifestyles and socio-economic factors," said Dr. Lewis Kuller, chairman of the department of epidemiology at the University of Pittsburgh School of Medicine.

Lifestyle factors that can influence the risk for heart disease include cigarette smoking, cholesterol levels and diet.

The states with the highest rates of death from cardiovascular disease are South Carolina, with 258.2 deaths per 100,000 people; Mississippi, with 256.1 deaths per 100,000; the District of Columbia, with 254 deaths; West Virginia, with 252.3 deaths; Louisiana, with 243.1 deaths; and Georgia, with 238.5.

The states with the lowest death rates are Hawaii, with 159.7; New Mexico, with 161.5; Colorado, with 169.3; Minnesota, with 174.3; Montana, with 177.1; and Arizona, with 178.

More research is needed to fully explain the variations, said Dr. Albert Oberman, director of the division of general and preventive medicine at the University of Alabama in Birmingham.

Between 1978 and 1988, the death rate from heart attacks dropped by 29.2 percent, deaths from stroke fell 33.2 percent and deaths from high blood pressure dropped 20.2 percent. Experts attribute the gains primarily to healthier lifestyles.

But heart disease remains the nation's leading killer, claiming the lives of nearly 1 million Americans, which is more than twice the death toll from all types of cancer.

The heart association also said that although women have nearly as many fatal heart attacks as men, they are far less likely to get bypass surgery.

Angioplasty, in which a balloon-like device is threaded into blocked arteries and used to force them open, was done 67,000 times in women and 160,000 times in men.

The heart association gave no explanation for the differences in treatment.