The authors of the study analyze various definitions of chronic heart failure (CHF). CHF, having many faces, despite the consensus concerning the paradigm of its pathogenesis, is given different definitions, using both the syndromic and nosological approaches. Most authors share a view of CHF as the final stage (outcome or complication) of many diseases in which there is impairment of ventricular filling or ejection of blood, i.e. as a syndrome, and not an independent nosological form. Nevertheless, at the beginning of the XXI century leading Russian specialists in heart failure presented a reasoned point of view on CHF not only as the final stage of the cardiovascular continuum, complicating the course of a disease of the cardiovascular sy...