Wong BM, et al. - Researchers conducted this investigation to better comprehend the burden of disease in patients with atrial fibrillation (AF) for whom rhythm control has not been successful or attempted and identify opportunities for improved care. At two academic emergency departments, they performed a health records review of consecutive AF patient visits. Participants in the study were patients ≥ 18 years with AF, heart rate ≥ 100 beats per minute, and who were not successfully cardioverted or not attempted cardioversion. Investigators found that the majority of patients experienced a rapid rhythm secondary to a medical cause. Findings revealed that there have been a concerning number of adverse events associated with suboptimal use of rate control. Better guideline knowledge will guarantee that rate control is used more safely.