Assessment of the Vascular Effects of PC6 (Neiguan) Using the Second Derivative of the Finger Photoplethysmogram in Healthy and Hypertensive Subjects

Abstract

Indices obtained from the second derivative of the digital volume pulse waveform have been proposed to characterize vascular aging, arterial rigidity, and the effects of vasoactive drugs. The purpose of this study was to assess the effects of manual needling of PC6 on SD(DVP) indices in healthy and untreated hypertensive subjects. AI, B:A, and D:A indices, based on the height of the wave components of SD(DVP), in 40 healthy subjects and 25 untreated hypertensive subjects were compared. DVP was obtained by measuring infrared light transmission through the finger. For each subject, 20-min-long DVP registration was obtained. PC6 was stimulated unilaterally by manual needling for 5 min (1-6 min). In each subject, pre-acupuncture DVP indices were compared to those of during acupuncture (1 vs. 4 min) and post-acupuncture (1 vs. 18 min). In healthy subjects, AI was significantly improved when comparing the pre- to the post-acupuncture values. In hypertensive subjects, the SD(DVP) indices improved significantly as follows: the AI index when the value of pre-acupuncture comparing to that of during acupuncture and post-acupuncture values; B:A and D:A indices when the pre-comparing to post-acupuncture values. There were significant differences between healthy and hypertensive subjects in AI, B:A, and D:A at baseline and in B:A in the during acupuncture period; there were no significant differences at post-acupuncture. These results indicate that manual needling of PC6 produced acute effects on vascular pathophysiology. Moreover, PC6 needling produced changes in SD(DVP) indices related to both large artery stiffness and the reflected wave originating in small arteries.

Effect of acupuncture and instruction on physiological recovery from maximal exercise: a balanced-placebo controlled trial

“…All acupoints were carried out bilaterally except REN17. The rationale for these points was based on the consistent physiological effect of PC6 and ST6 on cardiovascular function [ 2 , 23 , 24 ], while LU7 is applied for promoting lung function [ 25 ] and REN17 is indicated for regulating Q i in the chest and treating breathlessness [ 26 ]. PC6, ST36, and LU7 have been used in previous research evaluating the effect of acupuncture on exercise recovery [ 14 , 27 ] and exercise performance [ 21 ].…”

Evaluation of Cardiorespiratory Function During Cardiopulmonary Exercise Testing in Untreated Hypertensive and Healthy Subjects

“…It has been shown that b/a is significantly decreased with atherosclerosis (Imanaga et al, 1998 ). It has also been reported that b/a reflects the distensibility of large arteries (Rivas-Vilchis et al, 2007 ), and the difference of distensibility of large arteries also suggested the different response of systolic blood pressure in hypertension. Elevated SBP was associated with increase of arterial stiffness (Otsuka et al, 2007 ; Yousef et al, 2012 ).…”

“…In other words, d/a is associated with augmentation of blood pressure in the aorta by wave reflection, which in turn, is an indirect index of arterial stiffness (Tomoyuki and Toshiaki, 2013 ). The parameter AGI has been used to assess the vascular aging and for screening of arteriosclerotic disease (Rivas-Vilchis et al, 2007 ). In addition, the elevated AGI was associated with blood pressure, obesity and smoking, which can lead to higher aortic stiffness and can be even in the absence of atherosclerosis of the blood vessel (Mahmud and Feely, 2003 ; Tabara et al, 2008 ).…”

Standard Terminologies for Photoplethysmogram Signals

“…The second paper by Rivas-Vilchis et al in 2007, [26] when they used the photoplethysmogram to assess the vascular effects of PC6 (Neiguan) in healthy and hypertensive subjects.…”