Significance of neuro-cardiac control mechanisms governed by higher regions of the brain.

Advances in investigative techniques have led to an increasing awareness and understanding of the role of central neural control in the autonomic nervous system regulation of the heart. Substantial evidence exists for a role of the higher centres in neuro-cardiac control including the effect of focal brain stimulation and acute brain lesions on cardiac electrophysiology, blood pressure, contractile function and the development of arrhythmias. Mental stress and strong emotions have long been associated with sudden cardiac death. There is an emerging literature relating the gene-environment interactions in determining the neural patterning responsible for the stress response itself. The role of the higher brain centres in determining myocardial behaviour has become accessible through the utilisation of optogenetic techniques to modulate activity in specific brainstem nuclei, enabling the dissection of specific vagal and sympathetic inputs on cardiac electrophysiology and arrhythmogenesis. Central cardiac control mechanisms are modulated by afferent signals from the heart. Ascending interoceptive pathways from heart to several forebrain regions influence the behavioural response and autonomic output to the heart. These processes are expressed as control loops at multiple levels of the neuraxis and are assumed to converge in part at the level of the baroreflex to shape the efferent drive to the heart and vasculature.