Heart failure is a clinical syndrome due to a structural or functional cardiac disorder that impairs the ability of the ventricle to fill with or eject blood in order to deliver oxygen at a rate commensurate with the requirements of the metabolizing tissues.
Symptoms are caused by ventricular dysfunction secondary to abnormalities of the myocardium, pericardium, endocardium, valves, heart rhythm and conduction.
Chronic heart failure is a state where patient's signs and symptoms have been unchanged (stable) for at least a month but may decompensate suddenly or slowly when stable chronic heart failure deteriorates leading to hospitalization.