We performed retrospective analysis of 198 case reports of patients with first episode of non-valvular type I atrial flutter, among them 168 (84.8 %) men and 30 (15.2 %) women aged 55.1±0.8 years. Over five years of follow-up 13.1 % patients did not have arrhythmia, rare paroxysms were registered in 40.9 %, while frequent (at least once every three months) – in 7.6 % of patients. Permanent atrial fibrillation or flutter was registered in 38.4 % of patients. Drug restoration of sinus rhythm was successful in 18.8 % of patients, drugs plus electrical cardioversion (in case of medications inefficacy) – in 30.2 %, while only electrical cardioversion (including transesophageal stimulation) – in 51 % of patients. Patients with permanent arrhythmia were older compared to those with sinus rhythm (P=0.0002), more often they had coronary heart disease (P=0.0002), arterial hypertension (P=0.002), sick sinus node syndrome (Р=0.02), heart failure (Р=0.005) and concomitant oncological diseases (Р=0.0009).