According to new research published in the Journal of the American Heart Association, structural or functional abnormalities in the hearts left atrium, with or without symptoms, can increase a persons risk of developing dementia later in life by 35%. In the study, the research team aimed to determine the relationship between atrial cardiopathy and dementia, and if so, whether it is independent of atrial fibrillation and stroke.

In the heart, the left atrium is one of four chambers and is responsible for receiving blood from the lungs and pumping it into the left ventricle, which is then pumped to the rest of the body. An abnormality in the structure or functioning of the left atrium, known as atrial cardiopathy, often serves as a biomarker, or predictor, of a persons cardiac risk. Atrial cardiopathy is associated with an increased risk of stroke and atrial fibrillation, which are both linked to an enhanced risk of dementia.

The study results highlighted the relationship and mechanisms between a state of atrial dysfunction that may be subclinical (not presenting symptoms) and the newly uncovered association with dementia. Participants in the analysis were part of a larger study group of more than 15,000 people originally recruited for the ongoing Atherosclerosis Risk in Communities (ARIC) study, which began in 1987 to research heart health in people living within four diverse communities throughout the U.S. ARIC study. The researchers evaluated the cognitive decline in all participants with a comprehensive neuropsychological test battery from the Uniform Data Set of the Alzheimers Disease Centers program. When the researchers adjusted for participants who experienced atrial fibrillation and stroke, even after accounting for other vascular risks, they observed an increase of 31% and 28% in the risk of dementia in patients with atrial cardiopathy, respectively. 

(Source: https://www.hindustantimes.com/lifestyle/health/risk-of-dementia-might-be-higher-if-an-upper-heart-chamber-is-abnormal-101660291750675.html )