Is there a place for the late cardioversion of atrial fibrillation?. A long-term follow-up study of patients with post-thyrotoxic atrial fibrillation

AIMS: As atrial fibrillation is associated with significant mortality and morbidity, restoration of sinus rhythm is desirable. However, previous data suggest that cardioversion should be restricted to patients in whom the fibrillation is of limited duration (12 months (median duration 28.5, interquartile range 15-47 months). Cardioversion was attempted using disopyramide and then electric shock. Ninety-eight patients were successfully cardioverted: at late follow-up, 80.6+/-37 months (mean+/-SD), 67% were in sinus rhythm. CONCLUSION: Although a relationship between the duration of fibrillation and maintenance of sinus rhythm was found, the high proportion remaining in sinus rhythm, compared with other series, suggests this influence may be less important than the presence or absence of structural heart disease.