Extracardiac features of heart failure: Catecholamines and hormonal changes

Congestive heart failure is a very complex clinical syndrome characterized by a number of important extracardiac features. In an attempt to maintain circulatory homeostasis, there is activation of a number of vasopressor/Na⁺ retentive forces. Plasma levels of angiotensin, norepinephrine and vasopressin rise, likely contributing to heightened peripheral resistance and antidiuresis. These forces appear to be offset to some extent by vasodilator/Na⁺ excretion activity in the form of increased prostaglandins, atrial natriuretic factor, and dopamine. There is a complex interplay between these neurohumoral systems in heart failure which is just beginning to be understood.