Central and peripheral sympathetic activation in heart failure.

The sympathetic nervous system overdrive occurring in heart failure has been reported for more than half a century. Refinements in the methodological approaches to assess human sympathetic neural function have allowed during recent years to better define various aspects related to the neuroadrenergic alteration. These include (i) the different participation of the individual regional sympathetic cardiovascular districts at the process, (ii) the role of the central nervous system in determining the neuroadrenergic overdrive, (iii) the involvement of baroreflex, cardiopulmonary reflex, and chemoreflex mechanisms in the phenomenon, which is also closely linked to inflammation and the immune reaction, (iv) the relationships with the severity of the disease, its ischaemic or idiopathic nature and the preserved or reduced left ventricular ejection fraction, and (v) the adverse functional and structural impact of the sympathetic activation on cardiovascular organs, such as the brain, the heart, and the kidneys. Information have been also gained on the active role exerted by the sympathetic activation on the disease outcome and its potential relevance as a target of the therapeutic interventions based on non-pharmacological, pharmacological, and invasive approaches, including the renal denervation, the splanchnic sympathetic nerve ablation, and the carotid baroreflex stimulation. The still undefined aspects of the neurogenic alterations and the unmet goals of the therapeutic approach having the sympathetic activation as a target of the intervention will be finally mentioned.