Atrial Fibrillation (AF)
Atrial fibrillation (A-tre-al fi-bri-LA-shun), or AF, is the most common type of (ah-RITH-me-ah). An arrhythmia is a problem with the rate or rhythm of the heartbeat. During an arrhythmia, the can beat too fast, too slow, or with an irregular rhythm.
AF occurs if rapid, disorganized electrical signals cause the ‘s two upper – called the (AY-tree-uh) – to fibrillate. The term “fibrillate” means to contract very fast and irregularly.
In AF, pools in the . It isn’t pumped completely into the ‘s two lower , called the ventricles (VEN-trih-kuls). As a result, the heart’s upper and lower chambers don’t work together as they should.
People who have AF may not feel symptoms. However, even when AF isn’t noticed, it can increase the risk of . In some people, AF can cause pain or , especially if the heart rhythm is very…