Direct current cardioversion of established atrial fibrillation

Restoration and maintenance of sinus rhythm is a desirable end point in patients with chronic atrial fibrillation. If clinically indicated, external cardioversion using direct current is the method of choice in most centers. The results range from 20 to 90% and are highly influenced by the underlying etiology. A number of determinants including age, duration of atrial fibrillation, and size of left atrium are usually taken into account in the indications but have been recently questioned. The use of prophylactic antiarrhythmic therapy has been shown to reduce the recurrence of atrial fibrillation significantly, but concerns remain regarding the safety of this treatment. In patients who failed external cardioversion, shocks delivered within the right atrium according to a recently described technique may be attempted. The initial results are promising, as 83% of patients are successfully cardioverted and 46% of patients are in sinus rhythm at 12 months. This new technique offers an additional alternative in patients with chronic atrial fibrillation and may therefore reduce the incidence of frightening embolic complications.