Hypertrophic cardiomyopathy (HCM) is associated with an increased incidence of supraventricular and ventricular arrhythmias. Atrial fibrillation (AF) is the most common arrhythmia in HCM with a prevalence of 20% and an annual incidence of two percent per year. Inc- reased left atrial size and volume along with impaired left atrial function confer an increased likelihood of AF. The onset of AF is often accompanied by a decrease in functional status in conjunction with an increased risk of stroke and overall mortality.