Atrial fibrillation (AF) and its related disorder, atrial flutter (AFlut), are common abnormal heartbeats. Because they are similar and AFlut is rare compared to AF, they are usually treated similarly and discussed as one disorder. AF is an extremely common arrhythmia affecting more that 5% of the population over 65 years of age. It is an independent risk factor for death. AF is considered a progressive disease increasing in prevalence with age and converting from paroxysmal to permanent within a single individual. The projected lifetime risk of AF is 1 in 4 for men. AF occurs when there is an electrical short circuit in the top parts of the heart (atria). This causes the atria to beat at >300 times per min in an irregular and ineffective manor. This has two consequences. The blood tends to pool in the atria allowing for clotting. Second, the bottom parts of the heart (ventricles) beat too rapidly in response to impulses arising in the atria. The rapid ventricular contraction without adequate filling time results in a reduced ejection of blood. This can cause heart failure symptoms such as shortness of breath and reduced blood flow to organs resulting in lightheadedness or collapse.