Atrial fibrillation, the rapid and uncoordinated beating of the upper chambers of the heart, is a fairly common disorder that has been linked to an increased risk of blood clots and strokes. Now, researchers have found that dementia occurs quite frequently in the years following a diagnosis of atrial fibrillation.
Dr. Teresa S. M. Tsang at the Mayo Clinic in Rochester, Minnesota and colleagues identified 2837 patients first diagnosed with atrial fibrillation between 1986 and 2000, and who were followed until 2004.
Dementia was diagnosed in 299 patients during an average follow-up of 4.6 years. The incidence rate of dementia was more than three times higher in the overall group than among residents in the local county aged 50 years and older, the investigators report in the European Heart Journal.
The mortality rate was also higher among those with atrial fibrillation-related dementia compared to those who remained mentally intact.
In another analysis comparing their cohort with the age-matched general Minnesota population, the team estimated that atrial fibrillation increased the risk of dying by 80 percent prior to a diagnosis of dementia, and by approximately threefold after onset of dementia.
Tsang and her associates suggest that “silent” strokes or blood clots affecting blood flow to the brain may explain the increased risk of dementia linked to atrial fibrillation.