In those with arrhythmia, a decline in thinking skills started earlier and declined more rapidly, a study says. (Chris Ratcliffe/BLOOMBERG)
Cognitive Decline
A common heartbeat irregularity may spur memory loss in older people

THE QUESTION Various factors can contribute to diminished memory and thinking skills as people age. Might atrial fibrillation — a fast and irregular heartbeat — be among them?

THIS STUDY analyzed data on 5,150 men and women 65 and older (average age, 73) who did not have atrial fibrillation, the most common type of arrhythmia, at the start of the study and had never had a stroke. In about a seven-year span, 552 of them developed atrial fibrillation. Standardized tests, given each year, showed that cognitive problems developed at an earlier age and thinking skills declined more rapidly in those with the arrhythmia than in those without. For example, among people 80 to 85 years old, scores fell about 10 points (on a 100-point test) for those with atrial fibrillation, compared with a six-point drop for people without the disorder. People with atrial fibrillation earned scores indicative of more serious cognitive impairment or dementia about two years earlier than the others.

WHO MAY BE AFFECTED? People 65 and older. Atrial fibrillation can develop at any time in life, but it becomes more likely with age. In some people it occurs sporadically; in others it is chronic and long-term. Changes in some cognitive abilities — being a little forgetful, for instance, or taking longer to learn new things — are a normal part of growing old. Other problems, such as dramatic memory loss or confusion, are not considered normal, although what causes more serious cognitive issues is not always clear.

CAVEATS During the study period, some participants may have had an undiagnosed stroke, which could have affected their cognitive abilities. The study did not prove that atrial fibrillation causes cognitive decline but rather suggested a link between the heart and brain conditions.

FIND THIS STUDY June 5 online issue of Neurology.

LEARN MORE ABOUT cognitive decline at (click “c” in topic index). Learn about atrial fibrillation at

The research described in Quick Study comes from credible, peer-reviewed journals. Nonetheless, conclusive evidence about a treatment's effectiveness is rarely found in a single study. Anyone considering changing or beginning treatment of any kind should consult with a physician.