We performed retrospective analysis of 217 case histories of patients with first atrial flutter type I episode of nonvalvular genesis: 185 (85,3%) men and 32 (14,7%) women. Over 3 years of follow-up there were no arrhythmias in 23% of patients, rare paroxysms were registered in 45,2%, often paroxysms (at least once every 3 months) – in 8,3%, constant atrial fibrillation or flutter was registerd in 23,5% of patients, where in 60,8% of cases sinus rhythm was not restored or preserved during the first year. Medication heart rhythm restoration was administered in 23,3% of patients, medication combined with electric cardioversion (in case of medication inefficacy) in 27,6% of patients, while only electric cardioversion (transesophageal electric cardiac stimulation or electric impulse therapy) – in 49,1% of patients. Amiodarone was administered in 81,4% of the studied patients for medication arrhythmia treatment. In cases of preventive antiarrhythmic treatment with amiodarone, its antiarrhythmic effects were registered in 36,8% of patients, proved amiodarone inefficacy in 28,9% of patients, amiodarone-induced thyroid pathology in 19,7% of patients, other amiodarone-induced disorders in 7,9% of cases, while its efficacy was evident only in 6,6% of case histories. Patients with preserved constant arrhythmia over three years were older compared to the patients with sinus rhythm (p=0,005), they more often had verified coronary arteries disease (p=0,002), arterial hypertension (p=0,009),
stage 2A heart failure (p=0,01), diabetes mellitus (p=0,03), oncology (p<0,0005), and stroke in anamnesis (p=0,03).