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Atrial fibrillation

Atrial fibrillation (AF) is the most common abnormal heart rhythm. The electrical system of the heart sends predictable signals, spaced regularly, to tell the heart muscle to contract. The heart has two upper chambers called atria, and two lower ones called ventricles. In normal conditions each signal begins on the side of the atria and travels to the other parts of the heart.

AF occurs if rapid, disorganized electrical signals cause the heart’s two upper chambers called the atria to fibrillate (contract very fast and irregularly). Some of the signals do not reach the ventricles, causing them to continue pumping, rapidly and irregularly. This irregular rhythm can reduce the efficiency of the heart to pump blood through the body. The blood accumulating in the heart chamber can form clots which can break off, travel to different parts of the body and cause an ischemia (decreased blood flow to an area and consequently lack of oxygen and nutrients).


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