Study design and setting
This is a retrospective observational study of patients who presented to the ED between January 1, 2010, and December 31, 2018, with a diagnosis of AF for > 48 hours who then underwent a TEE. All of the TEEs were ordered from the ED, but the actual examination was performed by a board-certified cardiologist with additional training and extensive experience with this procedure. Of the patients who did not have an atrial clot or other contraindication to cardioversion, there was a convenience sample who returned to the ED for electrical cardioversion performed by emergency physicians versus a second group who were cardioverted in the cardiology department. Regardless of the place where electrical cardioversion was performed, all patients were sedated for the procedure and received anticoagulation both before and after their cardioversion as per protocol. The study site is a 1000-bed tertiary care medical center that includes a comprehensive cardiology department. Over 90,000 adult patients are seen annually in the ED. The Institutional Review Board waived the requirement for written consent as this was a retrospective study.