 DEFINITION OF HEART FAILURE ESC GUIDELINES 2012 It defines heart failure or an abnormality of the structure of the cardiac function that involves an insufficient ability of the heart to provide for the oxygen requirements in relation to the metabolic demands of the tissues, despite normal or increased filling pressures. Heart failure is a syndrome that is characterized by the presence of typical symptoms dyspnea, peripheral edema and fatigue and signs resulting from an abnormality of cardiac structure and function. 