The management of atrial arrhythmias aims not only to restore sinus rhythm but also to maintain it. Ten to thirty per cent of patients have early recurrence of atrial arrhythmias, the treatment of which remains empiric. The aim of this study was to define factors predictive of early recurrence of atrial arrhythmias and the consequences on the length of hospital stay. A series of 131 patients who underwent reduction of atrial arrhythmias by electrical cardioversion was studied retrospectively. A recurrence within 24 hours was observed in 12.2% of the patients. These recurrences significantly increased the length of hospital stay (6.8+/-6.3 versus 3.6+/-3.8 days, p=0.005). This study confirms two previously reported results with respect to more long-term recurrences. In the "early recurrence" group, the duration of the atrial arrhythmia was longer (p=0.003) and there were fewer treatments with amiodarone (p=0.03). In addition, original results were obtained. In the "early recurrence" group, the patients were more often treated with furosemide (p=0.02), class Ic antiarrhythmics (p=0.007) or anaesthetised with thiopental (p=0.002) than patients without early recurrences. Experimental data explain these results. However, they require confirmation by a prospective randomised trial.