Pathophysiology of heart failure

Heart failure is a complex syndrome in which the patient typically has shortness of breath at rest or during exercise and/or fatigue. Heart failure begins after an “index event” that produces a decline in pumping capacity, which as a consequence activates compensatory mechanisms. This initial event may be myocardial infarction in patients with coronary heart disease, long-standing arterial hypertension, diseases of the valves, heart muscle disease itself, and more rarely other disorders, such as myocarditis. To overcome the detrimental effects of this initial event, the compensatory mechanisms (e.g., the adrenergic nervous system, the renin–angiotensin–aldosterone system, the cytokine system) are activated, which in the short term stabilize myocardial function; however, activated in a long-term manner, these mechanisms will lead to further systemic and cellular changes compromising cardiac function.