Heart failure is a syndrome and not a single pathological process.

The syndrome of heart failure is common and readily recognised:

• the patient complains of symptoms of breathlessness and exhaustion at rest or with less than the normal degree of exertion
• the functional reserve of the heart is grossly reduced
• there are associated changes in many organ systems

Heart failure may be acute or chronic:

• acute heart failure has a dramatic presentation:
• dyspnoea
• oedema, either pulmonary or peripheral
• organ underperfusion
• tachycardia

• chronic heart failure may be more insidious:
• chronic exercise limitation

A syndrome which may present similarly to heart failure is seen in patients with normal hearts who have extreme pressure or volume stresses.