As a result of the examination of 62 patients with non-coronarogenic ventricular arrhythmias (42 patients with idiopathic ventricular arrhythmias from the area of the right/left ventricle outflow tract and 20 ones with the right ventricle arrhythmogenic dysplasia) including endocardial electrophysiological study and of the data of subsequent radiofrequency ablation, the criteria of localization of arrythmogenic focus are determined on the basis of the data of standard 12-lead electrocardiogram and a simple algorithm of topic diagnostics was developed.