We performed retrospective analysis of 228 cases of first episode of non-valvular type I atrial flutter (AF): 201 (84.5 %) men and 37 (15.5 %) women. The mean age of patients was 55 years. Efficacy of medications for
arrhythmia treatment was 36.9 %, transesophageal cardiac stimulation – 94 %, electric cardioversion – 100 %. Recurrent paroxysms during one year after sinus rhythm restoration were observed in 24.1 % of patients, while in 59.4 % patients there were no recurrent episodes; in 83.5 % of patients there was no sense in antiarrhythmic treatment (AAT). Maximal frequency of recurrent paroxysms (8 %) and sustained arrhythmia (8.3 %) was observed in one month after cardioversion. Patients with permanent form of arrhythmia during one year of follow-up (13.9 %) were older than patients with sinus rhythm (P=0.03), they had more frequent arterial hypertension stage 3 (P=0.002), history of stroke (P=0.002), sick sinus node syndrome (P=0.01) and AF duration over 180 days (P<0.00001). During long-term follow-up maximal frequency of recurrent paroxysms during one year was observed in 47 % of patients, during 2 years – in 28.4 % and during 3 years – in 12 % of patients.