A type of irregular heartbeat, atrial fibrillation is characterized by rapid and irregular beating. This causes the ventricles to receive too little blood. At the same time, blood may congest and clot in the atria. These clots can enter the bloodstream and reach the brain, causing stroke. Atrial fibrillation disrupts the conduction of electrical impulses to the lower heart chambers. This can cause a quick, slow or irregular heartbeat. Atrial fibrillation is the most common heart rhythm disorder (cardia arrhythmia). Two out of every hundred people in developed countries are affected by this disorder. As populations age, atrial fibrillation will become more common.1 Generally, atrial fibrillation is not life-threatening; however, patients have a high risk of stroke. Visit your doctor if you experience the symptoms below and are concerned you may have atrial fibrillation.