[Interrelation between typical atrial flutter and atrial fibrillation: two sides of the same coin].

A range of clinical studies have shown that typical atrial flutter (AFI) is often accompanied by attacks of atrial fibrillation (AFib), and vice versa. Probably, these two forms of cardiac arrhythmia have common electrophysiological mechanisms. The combination of both forms is highly resistible to pharmacotherapy. Hybrid therapy including conservative treatment with antiarrhythmic drugs, catheter radiofrequency ablation and electrocardiostimulation is used widely and more effective in treatment of AFI accompanied by AFib. Up-to-date knowledge of heart electrophysiology has allowed substantial advancement in understanding interrelations between these two frequent arrhythmias, and made it possible to improve the results of treatment. However, it is not quite clear yet if there is an interconnection between the etiology of AFib and that of AFI, and what therapeutic strategy should be applied to patients with the combination of AFI and AFib.