[Decreasing heart rate and shortening of the arterial pulse propagation time by acupuncture in the spectral analyses].

By utilizing NAITO's analytical indices of the high frequency energy (HFEI) [sigma p x f (0.15 Hz < frequency < 0.45 Hz)] and the low frequency energy (LFEI) [sigma p x f (0.025 Hz < f < 0.15 Hz)] of R-R intervals combined with UEDA's index of fluctuation in propagation time of radial arterial pulses (i.e. R-P intervals), the author investigated relation between elongation in R-R and shortening in R-P intervals by application of electrical acupuncture (1 Hz) on traditional acupoints (HT7:SHENMEN and PC4: XIMEN). The spectral heart rate analyses have been performed in 16 males and 14 females (total 30, i.e. 18 physically healthy volunteers and 12 patients). Those who were suffering from any cardiovascular diseases were excluded. Results obtained are as follows; (1) The mean R-R intervals were significantly prolonged from 10 minutes after needle insertion to the end, i.e. 10 minutes after removal of the needles. (2) The R-P intervals were significantly shortened after 10 minutes of needle insertion. It is assumed that the decrease in heart rate by acupuncture was due to relative superiority of the vagal tone and the shortened R-P intervals, and was due to sympathetic nerve activities stimulated by acupuncture, so as to expedite arterial pulse wave propagation by the arterial contraction. Thus, increased activities of both sympathetic and vagal nerves can coexist simultaneously during acupuncture.