Atrial fibrillation (AF) is a growing clinical problem.1 AF is a highly dynamic condition involving episodes of sinus rhythm interspersed with periods of arrhythmia, becoming more difficult to terminate over time. AF carries a substantial cost, morbidity and mortality burden. There are two important approaches to the management of AF: 1). Controlling ventricular response rate without attempting to terminate or prevent AF (rate control), and 2). Attempting to control and maintain sinus rhythm (rhythm control).2 Current rhythm control with antiarrhythmic agents (AAD) is only moderately beneficial in restoration and maintenance of sinus rhythm but produce serious adverse events. AAD selection is limited based on the potential for pro-arrhythmia, patient's age, presence of structural heart disease, and renal or hepatic dysfunction. All AF anti-arrhythmic agents are associated with harm (number needed to harm 17-119).3 There remains an important need for development of an efficacious safe AAD for the control of AF. Recent published translational studies suggest that that neuronal-type Na+ channel blockade (nNav) with riluzole, a nNav inhibitor used to manage amyotrophic lateral sclerosis (ALS), can effectively suppress triggered atrial arrhythmias.4 In two independent retrospective cohorts, riluzole-treated ALS patients significantly lowered the incidence of new-onset AF. Riluzole is well-tolerated without evidence of pro-arrhythmia.5 Therefore, to assess riluzole's effects on the reduction of paroxysmal episodes of AF, we will conduct a prospective, randomized, placebo-controlled human study using holter monitors that offer continuous electrocardiographic monitoring pre- (1 month) and with exposure to riluzole or placebo (1 month) to determine statistically superior reductions in episodes of AF.