What is the main cause of AFib?

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.

Listen to pronunciation. (AY-tree-ul fih-bruh-LAY-shun) An irregular heartbeat that occurs when the electrical signals in the atria (the two upper chambers of the heart) fire rapidly at the same time . This causes the heart to beat faster than normal.

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.

The three main types of atrial fibrillation (A-fib) are: paroxysmal, persistent, and long-term persistent . Doctors also categorize A-fib as either valvular or nonvalvular. In some people, A-fib causes no symptoms, and a doctor might only discover it when testing for something else.