[Neurohumoral regulation in heart failure]

In the early phase of asymptomatic left ventricular dysfunction, neurohumoral systems are activated and are closely associated with the deterioration of left ventricular function and the progression into symptomatic heart failure. Congestive cardiac failure is characterized by an increasing activation of the sympathetic nerve activity, the renin angiotensin aldosterone system, vasopressin and endothelin. Together with a reduced endothelial formation of NO, the activation of neurohumoral systems leads to vaso-construction and retention of sodium and water, and by this, to a deterioration of cardiac function. On the other side, systems are activated like prostaglandins, ANP, BNP, dopamine and bradykinin, which act as vasodilators and increase natriuresis and diuresis. In the early phase of cardiac failure, natriuretic and vasodilator mechanisms are able to counteract vasoconstrictor factors, preventing by this unfavorable effects on left ventricular function.