Aging white adults appear to have a greater risk of developing the heart rhythm disorder atrial fibrillation than their black peers, new research suggests.

In a 17-year study, researchers found that 1 in 5 white men and 1 in 6 white women developed atrial fibrillation by the time they turned 80 years old, compared to 1 in 9 black men and women.

Atrial fibrillation, also known as AF, is the most common heart arrhythmia in the U.S., affecting about 2 million people. During an episode of AF, abnormal electrical activity in the heart causes its upper two chambers to beat in a rapid, uncoordinated rhythm; the arrhythmia itself is not life-threatening, but over time AF can contribute to stroke or heart failure in some people.

Dr. Alvaro Alonso, of the University of Minnesota in Minneapolis, and colleagues determined the incidence of AF among 15,792 men and women, who were between 45 and 64 years old when they entered a long-running study of cardiovascular disease called the Atherosclerosis Risk in Communities, or ARIC, study.

During 17 years of follow-up, the investigators identified 1085 new cases of AF in this group.

While the prevalence of heart disease risk factors, such as high blood pressure, diabetes, unhealthy weight, and smoking, was higher in blacks than whites, blacks had a 41 percent lower risk of AF than whites.

Among study participants free of AF at age 50, the cumulative risk for developing the disorder by the age of 80 was 21 percent for white men and 17 percent for white women, compared with 11 percent for black men and women.

The current findings suggest that AF is a significant health problem, particularly among the elderly, Alonso noted in an email to Reuters Health.

In light of their findings, Alonso and colleagues call for the development of AF prevention programs for aging adults.

SOURCE: American Heart Journal, July 2009.