What is fibrillation caused by?

Definition of fibrillation 1 : an act or process of forming fibers or fibrils . 2a : a muscular twitching involving individual muscle fibers acting without coordination. b : very rapid irregular contractions of the muscle fibers of the heart resulting in a lack of synchronism between heartbeat and pulse.

During atrial fibrillation, the heart’s upper chambers (the atria) beat chaotically and irregularly — out of sync with the lower chambers (the ventricles) of the heart . For many people, A-fib may have no symptoms. However, A-fib may cause a fast, pounding heartbeat (palpitations), shortness of breath or weakness.19 Eki 2021

Atrial fibrillation (AF) is a form of arrhythmia, or irregular heartbeat, in which the atria (the two small upper chambers of the heart) quiver instead of beating effectively . It is one of the most common forms of cardiac arrhythmia, affecting 0.4% of the general population and 5 to 10% of persons over 65 years of age.

The basic cause of AFib is disorganized signals that make your heart’s two upper chambers (the atria) squeeze very fast and out of sync . They contract so quickly that the heart walls quiver, or fibrillate. Damage to your heart’s electrical system can cause AFib.