Increased incidence of spontaneous conversion to sinus rhythm in patients with paroxysmal atrial fibrillation

BACKGROUND: The aim of our study was to evaluate spontaneous conversion rate to sinus rhythm in patients with paroxysmal atrial fibrillation (AF) not submitted to any treatment (pharmacological and/or electrical). METHODS: From January 1985 to September 1990, 123 consecutive patients with paroxysmal AF were hospitalized in our department. In 11 patients arrhythmia was due to arrhythmogenic conditions; 34 patients were submitted to emergency treatment with drugs (23 cases) or electrical cardioversion (11 cases); 78 patients (41 males; mean age 65.1 years; 37 females: mean age 68.6 years), without emergency problems were enrolled in our study and were submitted to a four-day observation period without any therapy, except in case of worsening. 35 patients were free from heart disease; in the other 43, 28 had chronic coronary disease, 11 hypertensive cardiovascular disease, 2 rheumatic valvular disease, 1 hypertrophic cardiomyopathy and 1 chronic cor pulmonale. RESULTS: In all 78 patients sinus rhythm was restored spontaneously - in about 90% of them within 24 hours. Mean time to conversion was 21 hours (range 1-96 hours). Cardioversion occurred in similar percentage and at the same time in both subgroups of patients (with and without heart disease). CONCLUSIONS: Therefore, given the risks and cost of every treatment, a 24-hour observation period without therapy could be useful in those patients presenting with paroxysmal atrial fibrillation without emergency problems.