RESUMO
INTRODUCTION: Atrial fibrillation (AF) is a relatively common arrhythmia. When AF represents an electrophysiological phenomenon in structurally normal hearts, it is termed lone AF. This study was a retrospective, case-based analysis of patients attending the Cardiac Clinic at Groote Schuur Hospital (GSH) and describes the clinical characteristics and outcomes of patients classified as having lone atrial fibrillation. To the best of our knowledge there are no such studies reported from Africa. METHODS: This was a retrospective, descriptive study in which 289 medical records of patients with AF at the GSH Cardiac Clinic were reviewed from 1992 to 2006. The clinical data were interrogated to exclude identifiable causes of AF. Information on clinical characteristics and outcomes were entered into a data-entry form. Baseline descriptive statistics were expressed as means and range for continuous variables, and counts with percentages for categorical variables. RESULTS: Fifteen per cent (n = 42) of patients were identified as having lone AF, with a mean follow-up time of 5.8 years. Males comprised 57% (n = 24) and females 43% (n = 18). Fifty per cent (n = 21) of the patients had paroxysmal AF, 29% (n = 12) had persistent AF, and 12% (n = 5) progressed from paroxysmal to permanent AF. Subsets of lone AF included concomitant atrial flutter (17%) (n = 7) and sick sinus syndrome (21%) (n = 9). Complications were stroke (10%) (n = 4), tachycardia-related cardiomyopathy (17%) (n = 7) and bleeding complications on warfarin (11%) (n = 3). CONCLUSIONS: Lone AF is not an uncommon arrhythmia, with a preponderance in thin, middle-aged males. The symptoms of lone AF can be debilitating. It has associated morbidity, including tachycardia-related cardiomyopathy and thromboembolism. Rate control and appropriate anticoagulation are the cornerstones of patient management.