Biphasic cardioversion of acute atrial fibrillation in the emergency department

Introduction: There is a trend towards accelerated management of acute atrial fibrillation (AF) in the emergency department (ED). We report our experience with biphasic cardioversion of acute AF. Methods: This was a prospective, descriptive study at a tertiary hospital ED over a 6 month period. Acute AF was defined as symptoms that had been present for < 48 hours. Patients who received biphasic cardioversion for acute AF in the ED were enrolled. Data collected included: patient demographics, past medical history, details of biphasic cardioversion, outcome, complications, disposition, and length of stay. Results: There were 34 attempts at cardioversion in 33 patients. The mean (SD) age was 56 (16) years and 21 patients (64%) were men. Biphasic cardioversion was successful in 31 attempts (91%). In 24 attempts (71%), 100 J was selected as the initial energy level. This was successful in 21 attempts (88%). There were three minor complications related to sedation. The mean (SD) length of stay was 5.6 (2.8) hours in the ED and 15 (25) hours in the hospital. The three patients who failed to revert were older (mean age 64 years), had underlying cardiovascular disease, and spent longer in hospital (50 v 12 hours, p = 0.01). Telephone follow up was conducted with 32 patients (97%) at 3 months. Recurrence of AF occurred in 7 patients (22%). Most patients (31, 97%) were satisfied with the biphasic cardioversion. Conclusions: Biphasic cardioversion of acute AF is effective. The majority of patients can be managed as outpatients, and there is very high patient satisfaction with this approach. An initial shock energy level of 100 J is usually effective.