A value is calculated by combining the results of these two measurements. The changes between beats are extremely small but can be measured very accurately electronically. Diabetes and age are common causes of autonomic nerve dysfunction. If you are beginning an exercise program and have autonomic impairment, your heart rate will not go to the age-related target levels for maximal exercise. If you try to reach age-related target levels, the heart may just stop.
Sensory nerves travel with the autonomic nerves, and both are damaged by the same process.
A heart attack may be imminent. Again, this can be treated and the heart attack avoided. Treatment for autonomic nerve dysfunction is similar to that for peripheral neuropathy. Medicines to increase blood supply to the nerves, good glucose control, and especially good metabolic control are important. When you have symptoms of affected organs, treatment is directed to the symptoms as well.