Natural History of and Risk Factors for Idiopathic Atrial Fibrillation Recurrence (FAP Registry)

The natural history of idiopathic atrial fibrillation is not well understood. The aim of this study was to investigate the frequency of and risk factors for disease recurrence. The study involved 115 patients with a first episode of paroxysmal atrial fibrillation of unknown origin who were included the FAP registry, which contains data from 11 district hospitals in Catalonia, Spain. All patients underwent comprehensive clinical, laboratory, electro-cardiographic and echocardiographic investigations at ba-seline and were followed up periodically every 6 months to identify the occurrence of new symptomatic episodes and their complications. During a mean follow-up period of 912 (445) days, 32 (27.8%) patients experienced recurrence of atrial fibrillation. Those who experienced recurrence had a significantly higher left ventricular ejection fraction ( P=.023) and smaller end-systolic volume ( P