Autonomic control of the aging heart.

Cardiovascular diseases including hypertension, myocardial infarction, stroke, and heart failure continue to account for the majority of deaths in the developed world. Whilst the incidence of these clinical disorders does increase with age, outcomes in affected patients tend to be disproportionately adverse with advancing years. In this context it is important to understand the various compensatory processes which become activated in cardiovascular disease. In particular, the autonomic nervous system is known to play a key pathogenic role in the cause and response to many of these conditions. The normal aging process is accompanied by a complex series of changes in the autonomic control of the cardiovascular system, favoring heightened cardiac sympathetic tone with parasympathetic withdrawal and blunted cardiovagal baroreflex sensitivity. Together these changes have the potential to further magnify the effects of concomitant cardiovascular disease. Attention to the mechanisms of these changes and the development of appropriate therapies may serve to reduce the added influence of age on outcome in patients experiencing cardiovascular disease.