Heart failure is a clinical syndrome characterized by symptoms (dyspnea, edema, fatigue) and/or clinical signs of fluid retention (increased central venous pressure, pulmonary crepitations , peripheral edema). This is caused by a structural or functional dysfunction of the heart, which increases intracardiac pressure, decreases cardiac output at rest and/or during exercise, and causes fluid retention.

When the diagnosis of heart failure is made, we describe the patient's cardiac status using a combination of these 3 classifications: 

• the clinical status: acute versus chronic heart failure .
• the degree of dyspnea, expressed according to the NYHA class .
• the left ventricular ejection fraction (LVEF) .

These classifications, as well as the underlying etiology of the heart failure, determine the indicated treatment. When a diagnosis of heart failure is made, a diagnostic assessment must always be made in order to determine the cause, if possible, and to initiate correct treatment.