Atrial fibrillation. Cause and time of onset.

To characterize groups of patients presenting at the emergency room with atrial fibrillation (AF) according to the various causes of AF and the time of its onset, 704 medical files from the Beilinson Medical Center (Petah Tikva, Israel), during an eight-year period, were reviewed. Two thirds of all patients converted to sinus rhythm (SR) within a seven-day in-hospital treatment. The most frequent causes associated with AF were atherosclerotic cardiovascular disease, 55%; rheumatic heart disease, 22.8%; chronic obstructive pulmonary disease, 2.8%; Wolf-Parkinson-White syndrome, 2.6%; and thyrotoxicosis, 2.6%. There was a relatively large group of idiopathic AF (4.5%). Best convertors to SR were patients with idiopathic AF (93.9%), then patients with Wolf-Parkinson-White syndrome (88.8%), followed by atherosclerotic cardiovascular disease (71.6%), and thyrotoxicosis (63.2%). Patients with rheumatic heart disease and chronic obstructive pulmonary disease had the lowest percentage of successful conversion to SR--46% and 55%, respectively. We conclude that there are differences regarding gender, age, and possible conversion of AF to SR according to the different causes of AF.