The findings showed that states in the Southeast and Southwest were heart disease leaders.

West Virginia and Kentucky — states known for high levels of obesity, diabetes and smoking — have the highest proportion of people with heart disease.

Colorado and the District of Columbia had the lowest percentages, followed by Hawai'i with the third-lowest rate. In Hawai'i, only 4.9 percent of people have had a heart attack, chest pain or narrowed arteries, according to the U.S. Centers for Disease Control and Prevention.

In West Virginia, more than 10 percent of the population have had such conditions.

Asian-Americans were the healthiest ethnic group nationwide. Fewer than 5 percent of them had any of the heart-health problems.

The results were the same for blacks and whites, with just over 6 percent having one of the conditions. American Indians and Alaska Natives had the highest prevalence, at about 11 percent.

The state-by-state results line up well with previous reports about heart disease death rates, obesity and other risk factors, said Wayne Rosamond, an epidemiology professor at the University of North Carolina who chairs a statistics committee for the American Heart Association.

He called the report by the U.S. Centers for Disease Control and Prevention "very important. It confirms what we know about regional differences in the burden of disease."

For the nation as a whole, roughly 4 percent of those surveyed had had a heart attack. A slightly higher percentage reported angina or coronary heart disease, and 6.5 reported any of those conditions.

But in West Virginia, more than 10 percent had at least one of the conditions. The prevalence in Kentucky was nearly 9 percent, and Mississippi was No. 3, with 8 percent.

CDC researchers drew their data from a 2005 telephone survey of 356,112 U.S. adults in all 50 states, the District of Columbia, Puerto Rico and the U.S. Virgin Islands.

Participants were asked if a doctor or healthcare professional had told them they had experienced a heart attack, angina, or coronary heart disease. The researchers then statistically adjusted the results to correct demographic differences in state samples to better mirror the U.S. census.

The prevalence in both Colorado and the District of Columbia was 4.8 percent, tying them for the nation's lowest rate.

The regional differences are believed to stem from rates of obesity, high blood pressure, high cholesterol, diabetes, smoking and other known risk factors for heart disease, said the study's lead author, Jonathan Neyer, a CDC epidemiologist.

That means the explanation would come from differences in cultural norms, poverty rates and other social factors, and not environmental causes, he said. "There's not something in the water," Neyer said.

Other findings: