To determine if a medication regimen (MET vs DT) is noted by descriptive analysis to be associated with primary aim 1 for treating AF/FL in the ED or during hospitalization (Primary Aim-1), the investigators will describe the proportion of patients with rhythm control (defined as normal sinus rhythm) by time of ED discharge using Chi-square analysis with continuity correction. Using the same statistical tests, the investigators will describe the proportion of patients with normal sinus rhythm at time of hospital discharge, in patients admitted to CAMC. Possible confounders, including patient characteristics, co-morbid conditions, ED events, or deviation from medicine regimen on achieving NSR will be examined by comparing patients with the confounder to those without the confounder of interest using Chi-square with continuity correction analyses if data is categorical, t-test or Mann-Whitney U analysis if data is continuous. In addition, the investigators will examine the effect of medication regimen on rate control (defined as heart rate < 100 bpm) (Primary Aim-2) at 2, 4, 6, 8 hours in the identical manner as described for rhythm control including the examination of confounding variables.