RESUMO
OBJECTIVE: To assess the relative frequency and clinical profile of paroxysmal lone atrial fibrillation in comparison with that of secondary atrial fibrillation. PATIENTS AND METHOD: A prospective multicenter study (FAP Register) was designed to include 300 patients with symptomatic paroxysmal atrial fibrillation admitted to the emergency ward of 11 secondary hospitals of Catalonia. RESULTS: Lone atrial fibrillation was found in 67 patients (22.3%) while systemic hypertension was present in 33.7% of the cases; mitral or aortic valvular disease in 12% and coronary heart disease in 9.7%. As compared with patients with evidence of cardiac or systemic etiology, patients with isolated paroxysmal atrial fibrillation were younger (mean age of 55 vs 65 years of age; p = 0.0001), dyspnea was less frequent (p = 0.007); had a tendency to appear at night; left atrial size was smaller (p < 0.001) and response to treatment of sinusal rhythm was not different. CONCLUSIONS: Relative frequency of paroxysmal lone atrial fibrillation was only second to hypertension, which appears to be the most important pathogenic factor in our population. The clinical profile shows similarities in secondary fibrillation
