Early study termination, early crossover, and procedures to treat persistent AF: Based on our prior clinical experience, a proportion of patients (20 to 30%) are expected to experience residual symptomatic episodes of AF while taking either or both study AADs. Usually these episodes will be less bothersome or lengthy. Patients will be encouraged to continue the study protocol if possible. However, a smaller proportion of patients might have intolerable symptoms necessitating an unscheduled change in therapy. The study team will work with the primary cardiac electrophysiologist to facilitate any necessary change in therapy. An early crossover to the alternative study AAD will be encouraged over a change to a non-study AAD when possible. A change in therapy to a non-study AAD or AF ablation procedure will be allowed when necessary. In addition, if patients acquire persistent AF during the course of the study, direct current cardioversion will be allowed and will be coordinated by the study team and the primary cardiac electrophysiologist. AF burden data for patients deviating from the study protocol will be analyzed using an "on treatment" analysis. In other words, the AF burden will be calculated per day that patients are on each study AAD. Patients will also be allowed to withdraw from the study for personal or other reasons at any time.