Heart Rate Variability
The overall functioning of the autonomic nervous system can be assessed very
easily with an in-office test called Heart Rate Variability (HRV). For this test a sensor is
attached to the chest area to record the heart beat for two minutes while the patient is lying down,
and for another two minutes when the patient stands. The results are then plotted, or graphed, to
reveal the activity of the sympathetic and parasympathetic nervous systems, with values ranging
between +4 to -4 for both systems.
Heart rate variability refers to the difference in length of each heart beat. For example,
you would conclude that if a person had a pulse rate of 60 beats per minute, then each beat would
last for one second. If each of the 60 beats lasted for one second, however, this would be a case
of no heart rate variability, and the patient would have definite symptoms of chronic disease.
If one beat lasted for 1.0 seconds, followed by the next beat at .98 seconds, followed by
the next beat at 1.02 seconds, followed by the next beat at .97 seconds, however, this would
indicate excellent heart rate variability, and this patient would be considered quite healthy (with
a positive reading on the parasympathetic nervous system). A decrease in, or lack of, heart rate
variability is a common risk factor for virtually all chronic diseases, regardless of a