Sample size: This proposed pilot/feasibility study is not expected to be adequately powered to detect a variable response to AADs based on chr4q25 genotype. Rather, this study will provide vitally important and currently unavailable data on mean and standard deviation of AF burden during therapy with the study drugs. These data will then be used to conduct a formal sample size calculation for the main trial. This study will also examine the feasibility of the crossover design which, if feasible, will be utilized for the main trial.