Atrial fibrillation (A-Fib) – a type of rapid or irregular heartbeat – has long been associated with stroke and brain infarctions. More recently, A-Fib has also been linked to dementia and cognitive decline. A new study from Dr. Lin Yee Chen, Associate Professor of Medicine in the Cardiovascular Division at the University of Minnesota Medical School, is exploring the possibility that A-Fib is perhaps only symptomatic of something further upstream: A large or abnormally functioning left atrium.

The study, “Left Atrial Abnormality and Atrial Fibrillation-Related Cerebral Infarcts and Cognitive Decline,” funded by an R01 grant from the National Institutes of Health's National Heart, Lung, and Blood Institute, could be a game-changer, says Dr. Chen.

“If we find out that you don’t need to have A-Fib to be at risk of stroke or cognitive decline, but just need an abnormal left atrium, it means we could start treatment sooner,” he says. “It could also open up the idea we have to target more upstream to prevent the development of left atrial abnormality in the first place.”

This new study is complementary to his current R01-funded project, “Significance of Atrial Fibrillation and Atrial Fibrillation Burden Detected by Novel ECG Monitoring in Community-Dwelling Elderly,” which attempts to determine the prevalence of silent or asymptomatic A-Fib and whether higher burden of A-Fib is associated with poorer health outcomes.

The data obtained from his current R01-funded study, in combination with echocardiographic imaging in the new study to measure left atrial function, will help uncover to what extent outcomes like cognitive decline and infarcts are associated with A-Fib or explained instead by the underlying abnormal left atrium.

“Our hypothesis is that increased left atrial size and impaired left atrial function that lead to a higher risk of A-Fib are also driving factors for the higher risk of stroke and dementia in people with A-Fib,” says Dr. Chen.

Read more about Dr. Chen's work.