[Prevalence and clinical features of atrial fibrillation in the north-west of the Russian Federation].

Incidence and prevalence of atrial fibrillation (AF) are analysed for the period from 1980 to 2004. They are shown to increase 5 and 6-fold respectively in the north-western region of Russia. Prevalence of AF in men increased 10-fold and in women 4-fold. Different incidence of AF among men and women was documented for the first time. Percentage of arterial hypertension, idiopathic AF, and diabetes mellitus increased among patients with newly diagnosed AF.