Transthoracic Versus Transesophageal Cardioversion of Atrial Fibrillation under Light Sedation: A Prospective Randomized Trial

Background:Electrical cardioversion (ECV) of atrial fibrillation (AF) is limited by a 5–10% failure rate and by the expense arising from a perceived need for general anesthesia. A transesophageal approach using light sedation has been proposed as a means of augmenting the success rate and avoiding the need for general anesthesia. We hypothesized that the high rate of success and the lower energy requirement associated with biphasic cardioversion might eliminate any advantage of the transesophageal approach. Methods:We randomly assigned 60 patients attending for ECV of persistent AF to a transesophageal or a transthoracic approach. Sedation of moderate depth was achieved with intravenous midazolam. The dose of midazolam was titrated in the same manner in both groups. Results:Sinus rhythm was restored in 29/30 patients (97%) in each group using a similar number of shocks for both groups (1.3 ± 0.6 transesophageal vs 1.4 ± 0.7 transthoracic, P = NS) with a similar procedure duration (14.1 ± 8.2 minutes vs 13.8 ± 7.5 minutes, P = NS). Both groups received similar doses of midazolam (4.2 ± 2.7 mg vs 4.4 ± 2.8 mg, P = NS) and both reported a similar discomfort score in (0.9 ± 1.3 vs 1.1 ± 1.8, P = NS). No complication occurred in either group. Conclusion:AF may be cardioverted safely and effectively by either a transthoracic or a transesophageal approach. The use of sedation of moderate depth renders cardioversion by either approach acceptable. As transesophageal ECV shows no clear advantage, transthoracic cardioversion should remain the approach of first choice.