Atrial fibrillation, the most common type of arrhythmia, is an irregular and often rapid heart rate that can increase your risk of strokes, heart failure, and other heart-related complications. During atrial fibrillation, the heart’s two upper chambers (the atria) beat chaotically and irregularly in a way that puts them out of coordination with the two lower chambers (the ventricles) of the heart.
Researchers from Sheba Medical Center, Tel Aviv University, Technion – Israel Institute of Technology, and Weizmann Institute collected epicardial fat from 32 patients with and 30 patients without atrial fibrillation during elective heart surgeries. The effects of these epicardial fat samples were then examined on induced pluripotent stem cell-derived cardiomyocytes in a lab environment. The result was excessive inflammation, scarring, and apoptosis.
According to Prof. Jonathan Leor from Sheba Medical Center’s Neufeld Cardiac Research Institute, one of the study’s senior researchers: “Our study shows that an accumulation of epicardial fat, resulting from overweight, is a major contributing factor to the development of atrial fibrillation, which can cause strokes, dementia, and heart failure.” Prof. Leor added that this is likely attributable to the fact that epicardial fat tissue “secretes hormones and pro-inflammatory molecules that damage the heart’s structure and function.”
Another important finding of the study was that epicardial fat tissue holds a relatively high concentration of the receptors used by COVID-19 to enter host cells, thus explaining the increased vulnerability of overweight individuals to complications associated with COVID-19.
The study was published in the cardiovascular health and disease medical journal Circulation.