A study has found that risk of dementia increases in association with atrial fibrillation; a disease affecting three million Americans.

Atrial Fibrillation occurs when rapid, disorganized electrical signals causes the heart’s chambers atria to fibrillate. "Fibrillate" means to contract very fast and irregularly. Atrial Fibrillation has been linked to increase risk of stroke which occurs when the flow of oxygen rich blood to the brain is blocked. Without oxygen, brain cells start to die after few minutes.

Researchers at Group health research Institute published their study in the journal of the American Geriatric Society.

"Before our prospective cohort study, we knew that atrial fibrillation can cause stroke, which can lead to dementia. Now we've learned that atrial fibrillation may increase dementia risk in other, more subtle ways as well." said Dr. Dublin, MD, PhD, a Group health research Institute assistant investigator who led the research.

Dublin’s research is part of Adult Changes in Thought (ACT), an ongoing joint project of Group Health and University of Washington studying dementia and its risk factors in older adults. They focus on finding ways to delay or prevent dementia including Alzheimer’s disease, and declines in memory and thinking.

Dublin’s studies followed 3,045 participants from 1994-2008 relying on advanced electronic data system to determine whether participants had atrial fibrillation. Tests were given every two years to measure dementia including brain scans.

Researchers found that after following participants in the study over a seven year period those with atrial fibrillation had a 40 to 50 percent greater risk of developing dementia of any type including Alzheimer's disease, compared to those without atrial fibrillation.

Dr. Dublin said an important next step is studying whether any treatments for atrial fibrillation reduce the risk of developing dementia. The researchers also hope their results reach primary care providers, who are often the main doctors caring for people with atrial fibrillation, dementia, or both.

"This paper is a wakeup call, telling us that we need to learn more about how to protect brain function, while continuing to give patients with atrial fibrillation the best possible care."