The study objective was to establish the supraventricular tachycardia frequency in children of the Republic of Belarus, to determine the structure and characteristics of those rhythm disturbances. An in-depth study of the properties of the heart conduction system was carried out in the course of the esophageal electrophysiological study included 203 children (younger 18 years). Supraventricular tachycardia was determined to be detected in children rarer in the neonatal period, during the first year of life being identified maximally often at the age of 17 years, concomitant pathologies found in children with supraventricular tachycardia comparatively rarely (11.8%).