抄録
To determine whether autonomic function evaluation by the coefficient of variation (CV) of the R-R interval can be used in otolaryngological diseases, we calculated the CV values in 88 cases of OD dizziness with and in 50 cases as control without autonomic disorders. These were automatically measured from 100 consecutive heart beats at 8 points of time:immediately after lying down, 5, 10, 15 and 20 minutes after the start of bed rest, immediately after standing up and 5 and 10 minutes later while still standing.
The CV value varied markedly even during rest. The mean value after 20 minutes of bed rest was significantly larger in the patients than in the control group, showing hyperresponsiveness of the parasympathetic nervous system. However, the increase after standing was less than in the control group, showing reduced reactivity. Thus, the static function and the dynamic function results were different. It was concluded that it is not appropriate to apply the conventionalmethod per se in evaluation and that the normal value itself is questionable sincethe method generally gives too large a CV and has quantitative significance only in specific diseases like diabetic autonomic neuropathy in which the CV is always small, and since the CV can vary with the lapse of time and with stimulation.
Therefore, when the CV value for the R-R interval is used as an indicator of autonomic function one must observe the dynamic changes during stimulation or find a more appropriate indicator.
