Atrial fibrillation, or AFib, is an abnormal heartbeat that occurs when the top chambers of the heart do not beat in a coordinated manner.
AFib may allow blood to pool in your heart, which may cause blood clots to form. If a clot leaves your heart, it can block an artery in your brain and cause a stroke.
A stroke can be very serious. More U.S. adults are disabled by stroke than by any other cause. A stroke may make it hard for you to move, talk, or think – it can even kill you. Every 4 minutes someone experiences a stroke.