Autonomic function and prognosis.

Autonomic nervous system function is assessed in the clinic by measuring resting heart rate, heart rate variability, or heart rate recovery following exercise. Each of these measures is a strong predictor of cardiovascular risk and all-cause mortality in primary and secondary prevention settings. These measures have been used to identify correlates of autonomic nervous system dysfunction at both the patient level (eg, obesity, diabetes, heart failure) and the environmental level (eg, smoking, social stress, air pollution). Future research must determine how to exploit the associations between autonomic system dysfunction and poor prognosis to improve patient outcomes.