Dangerous arrhythmias on the rise

The number of people with a dangerous heart arrhythmia is higher than previously estimated and increasing, researchers have found.

In a study of Minnesota residents, the incidence of atrial fibrillation rose more than 12% between 1980 and 2000, said the study, which was released online July 3 and appears in the July 4 print version of Circulation: Journal of the American Heart Assn. At that rate, the number of U.S. residents with the irregular rhythm will rise to 16 million by 2050 -- nearly three times previous estimates, researchers said.

Atrial fibrillation is a condition in which the heart’s upper chambers quiver instead of beating regularly. It increases the risk of stroke, heart failure, cognitive impairment and death.

Scientists don’t know the cause of the condition, but risk factors include high blood pressure, diabetes and valvular heart disease. Recent data have also indicated that obesity is a risk.