Evaluation of Autonomic Nervous System Function Using Heart Rate Variability Analysis During Transient Heart Rate Reduction Caused by Acupuncture

Key targets of signal transduction neural mechanisms in acupuncture treatment of cardiovascular diseases: Hypothalamus and autonomic nervous system

Background

Cardiovascular disease is the leading cause of death worldwide. As a traditional Chinese treatment method, acupuncture has a unique role in restoring the balance of the human body environment. Due to its safety, non-invasive nature, and effectiveness in treating cardiovascular diseases, acupuncture has been widely welcomed and recognized among the world. A large amount of evidence shows that acupuncture can effectively regulate cardiovascular diseases through the autonomic nervous system. The hypothalamus, as an important component of regulating the autonomic nervous system, plays an important role in regulating the internal environment, maintaining homeostasis, and preserving physiological balance. However, there is currently a scarcity of review articles on acupuncture signal transduction and acupuncture improving cardiovascular disease through the hypothalamus and autonomic nervous system.

Objective

This review delves into the transduction of acupuncture signals and their neural regulatory mechanisms on the hypothalamus and autonomic nervous system, elucidating their impact on cardiovascular disease.

Methods

Review the basic and clinical studies on acupuncture signal transduction mechanisms and the role of the hypothalamus and ANS in acupuncture treatment of cardiovascular diseases published in four English databases (PubMed, Web of Science, MEDLINE, and Springer Cochrane Library) and two Chinese databases (Wanfang Database and China National Knowledge Infrastructure Database) over the past 20 years.

Results

Through sensory stimulation, acupuncture effectively transmits signals from the periphery to the hypothalamus, where they are integrated, and finally regulate the autonomic nervous system to treat cardiovascular diseases.

Discussion

Acupuncture exhibits significant potential as a therapeutic modality for cardiovascular diseases by orchestrating autonomic nervous system regulation via the hypothalamus, thereby gifting novel perspectives and methodologies for the prevention and treatment of cardiovascular ailments.

Comparison of Hemodynamic Changes During Acupuncture Stimulation in Supine or Sitting Position in Human Subjects

Objective

Position change influences acupuncture-induced heart rate (HR) reduction, which is caused by a somatoautonomic reflex. However, the influences of position on the hemodynamic system-including HR, blood pressure (BP), and cardiac output (CO) during acupuncture-remains unclear. This study comprehensively compared cardiovascular changes induced by acupuncture in human beings supine and sitting positions.

Materials and Methods

Comprehensive measurements were made of 30 healthy male volunteers, including HR, stroke volume (SV), and BP, in a supine posture for 15 minutes. Manual acupuncture stimulation was performed at the left LI-10 point for 1 minute. After at least 1 week, the same protocol was performed with all subjects in a sitting position.

Results

Preacupuncture, there were increases in HR and BP, and decreases in SV and CO in the sitting position, compared with the supine position. Acupuncture stimulation induced HR reduction more when the subjects were in the sitting position, compared with them in the supine position. Acupuncture-induced increase in SV and decrease in diastolic BP were not different in either position. In the sitting position, CO decreased during acupuncture, compared with preacupuncture; this did not occur in the supine position.

Conclusions

The effects of acupuncture on the hemodynamic system changed between the supine and sitting positions in healthy young men. Autonomic nervous-tone influences acupuncture-induced cardiovascular changes through physiologic responses, including the somatoautonomic reflex and the baroreflex.

Cognitive and affective interaction with somatosensory afference in acupuncture-a specific brain response to compound stimulus

Introduction

Acupuncture is a clinical intervention consisting of multiple stimulus components, including somatosensory stimulation and manipulation of therapeutic context. Existing findings in neuroscience consolidated cognitive modulation to somatosensory afferent process, which could differ from placebo mechanism in brain. Here, we aimed to identify intrinsic process of brain interactions induced by compound stimulus of acupuncture treatment.

Methods

To separately and comprehensively investigate somatosensory afferent and cognitive/affective processes in brain, we implemented a novel experimental protocol of contextual manipulation with somatosensory stimulation (real acupuncture: REAL) and only contextual manipulation (phantom acupuncture: PHNT) for fMRI scan, and conducted independent component (IC)-wise assessment with the concatenated fMRI data.

Results

By our double (experimentally and analytically) dissociation, two ICs (CA1: executive control, CA2: goal-directed sensory process) for cognitive/affective modulation (associated with both REAL and PHNT) and other two ICs (SA1: interoceptive attention and motor-reaction, SA2: somatosensory representation) for somatosensory afference (associated with only REAL) were identified. Moreover, coupling between SA1 and SA2 was associated with a decreased heart rate during stimulation, whereas CA1 was associated with a delayed heart rate decrease post-stimulation. Furthermore, partial correlation network for these components demonstrated a bi-directional interaction between CA1 and SA1/SA2, suggesting the cognitive modulation to somatosensory process. The expectation for the treatment negatively affected CA1 but positively affected SA1 in REAL, whereas the expectation positively affected CA1 in PHNT.

Discussion

These specific cognitive-somatosensory interaction in REAL were differed from vicarious sensation mechanism in PHNT; and might be associated with a characteristic of acupuncture, which induces voluntary attention for interoception. Our findings on brain interactions in acupuncture treatment elucidated the underlying brain mechanisms for compound stimulus of somatosensory afferent and therapeutic contextual manipulation, which might be a specific response to acupuncture.

Heart Rate and Autonomic Nervous System Activity Relationship During Acupuncture Associated with Postural Change and Effect on Menopausal Symptoms: A Prospective Randomized Trial

Objective

The autonomic nervous system (ANS) has been assessed using heart rate variability (HRV), and HRV has been used to evaluate acupuncture. This study investigated the relationship between heart rate (HR) and ANS activity during acupuncture and postural change.

Materials and Methods

Subjects (48 menopausal women) were assigned randomly to acupuncture and sham groups. Japanese-style acupuncture at 7 points was performed weekly for 4 weeks. For sham treatment an acupuncture tube was pressed at the same 7 points. Measurements of HR were taken at: stage 1 (supine position before acupuncture; control); stage 2 (acupuncture for 10 minutes), and stage 3 (after standing for 10 minutes). During the experiments, the following HRV indices were obtained: high (0.15 - 0.40 Hz) frequency (HF) power and low frequency (LF) power/high frequency power ratio (LF/HF) as an index of the parasympathetic nervous system activity and sympathetic nervous system activity, respectively. Participants' menopausal symptoms were assessed using a visual analogue scale.

Results

Reduction in HR during needle insertion and removal was significantly lower than that of retention (P < 0.01). There was a significant positive correlation between HR reduction during insertion and removal of needles (r = 0.732; P = 0.000). HR decreased by ≥5% in 79% (19/24) of the acupuncture-treated subjects. HF was increased significantly during acupuncture, while LF/HF decreased during standing. Menopausal symptoms were alleviated significantly.

Conclusions

Stimulation during acupuncture-needle insertion and removal regulated ANS function, causing a decreased HR. This technique relieve patients' menopausal symptoms.

Changes in tendon blood circulation and heart rate variability after intermittent compression to patellar and Achilles tendons

BACKGROUND

The purpose of this study was to compare changes in tendon blood circulation and heart rate variability after intermittent compression to the patellar and Achilles tendons.

METHODS

Before the intermittent compression to tendons (3 min) and the recovery period (40 min), the blood volume and oxygen saturation of the patellar and Achilles tendons were measured using red laser lights. In addition, heart rate and ratio of low-frequency to high-frequency components of heart rate variability were measured.

FINDINGS

Blood volume and oxygen saturation of patellar and Achilles tendons significantly increased after intermittent compression stimulation (both p ≤ 0.001). There were no differences in increases of blood volume (p = 0.575) and oxygen saturation (p = 0.055) between patellar and Achilles tendons. For both tendons treatments, heart rate (p = 0.698) and ratio of low-frequency to high-frequency components of heart rate variability (p = 0.518) did not change during the experimental period. In addition, the change in blood volume for Achilles tendon was significantly correlated with that in heart rate but not ratio of low-frequency to high-frequency components of heart rate variability, whereas the change in blood volume for patellar tendon was not significantly correlated with that in the heart rate or ratio of low-frequency to high-frequency components of heart rate variability,.

INTERPRETATION

These results suggest that intermittent compression-induced changes in blood circulation were similar between patellar and Achilles tendons. In addition, the increase in blood volume after intermittent compression stimulation in the Achilles tendon would be related to the increased metabolism of the tendon.

Acupuncture Relaxation, Vigilance Stage, and Autonomic Nervous System Function: A Comparative Study of Their Interrelationships

Objective: During acupuncture stimulation, autonomic nervous system (ANS) function changes toward being parasympathetic-dominant, with a transient decrease in heart rate (HR). The aim of this research was to determine the relationships between cortical relaxation and vigilance as observed on background electroencephalograms (EEGs), HR, and ANS function during deep acupuncture. Materials and Methods: This comparative study was conducted at Teikyo Heisei University, in Toshima-ku, Tokyo, Japan, with 27 healthy male volunteers. After resting for 20 minutes, the men received manual acupuncture at LI 10 on the left forearm for 2 minutes at a depth of 15-20 mm at a 1-Hz frequency while undergoing concurrent EEG and electrocardiography (ECG) monitoring. Each subject described his level of comfort during acupuncture. HR; power ratios (normalized units [n.u.]) of EEG alpha, beta, delta, and theta waves; and HR variability (HRV) indices were calculated. Results: In the subgroup who experienced discomfort, delta and theta n.u. were decreased while alpha n.u. were increased, indicating increased vigilance and decreased relaxation. In the subgroup who experienced comfort, there were no significant changes. HRV indices suggested parasympathetic-dominant changes in both subgroups. Weak correlations were observed between a decrease of theta n.u. and sympathetic-dominant changes in HRV indices. Conclusions: Alterations in background EEG activities were not the primary factors changing ANS function to parasympathetic-dominant and decreasing HR, but these alterations related to a weak secondary factor changing ANS function. EEG activity by which cortical relaxation and vigilance were represented was the weak secondary factor changing ANS function during acupuncture; the primary factor might be supraspinal reflection.

Changes in Blood Circulation of the Tendons and Heart Rate Variability During and After Acupuncture

Objective: The purpose of this study was to investigate the changes in blood circulation of tendons and heart rate variability (HRV) during and after acupuncture in order to elucidate the mechanisms of acupuncture-induced changes in tendon blood circulation. Materials and Methods: During 10 minutes of acupuncture treatment and a recovery period of 40 minutes, blood volume (THb) and oxygen saturation (StO₂) of treated and nontreated tendons were measured using red laser lights. In addition, HRV was also measured during the experimental period. Results: THb and StO₂ of the treated tendons significantly increased during acupuncture, and then remained high during the recovery period. THb and StO₂ of the nontreated tendons did not change during acupuncture but gradually increased during the recovery period. In addition, the increase in THb of the nontreated tendons were significantly correlated with that of the treated tendons during the latter half of the recovery period. Heart rate (HR) continued to decrease during acupuncture and suddenly returned to the initial level after removal of the needle. The low-frequency (LF)/high-frequency (HF) ratio tended to increase during the recovery period. During the latter half of the recovery period, the changes in THb for both the treated and nontreated tendons were negatively correlated with the change in HR but not with changes in the LF/HF ratio. Conclusions: These results suggest that changes in blood circulation of tendons after acupuncture treatment were controlled by the autonomic nervous system, which could not be detected by HRV analysis.

Effects of Acupuncture Sensations on Transient Heart Rate Reduction and Autonomic Nervous System Function During Acupuncture Stimulation

Objective: During acupuncture stimulation, heart rate (HR) transiently decreases and autonomic nervous system (ANS) function becomes parasympathetic-dominant. To clarify the effect of acupuncture sensations (pain, De Qi), the effects of deep acupuncture sensations on HR and ANS functions were determined. Materials and Methods: In this comparative study at Teikyo Heisei University, Tokyo, Japan, 40 healthy, male student volunteers rested for 20 minutes before undergoing manual acupuncture to the Shousanli (LI 10) acupoint on the left forearm for 2 minutes at a frequency of 1 Hz, with concurrent electrocardiography. Depth of stimulation was 15-20 mm. These subjects described their subjective acupuncture sensations. Calculations were performed, using HR variability analysis to find HR and low-frequency (LF) normalized units (nu), the ratio of LF components to total components (as an index of sympathetic nervous system function), high-frequency (HF)nu, the ratio of HF components to total components (as an index of parasympathetic nervous system function), and LF/HF (as an index of sympathetic and parasympathetic balance). Results: For the final analysis, data were available for 32 subjects. Compared to before acupuncture, HR decreased during acupuncture. HR decreased when no acupuncture sensations or when weak De Qi sensations were perceived, and remained unchanged when acupuncture sensations without De Qi or strong De Qi were perceived. LFnu decreased, HFnu increased, and LF/HF decreased, regardless of pain or De Qi. Conclusions: Acupuncture stimulation reduced HR even without De Qi sensations and caused ANS function to be parasympathetic-dominant, irrespective of the perception of acupuncture sensations.

Acupuncture Treatment for Symptom Management in Atopic Dermatitis: A Study Protocol for a Randomized, Participant- and Assessor-Blind, Sham-Controlled Trial

Atopic dermatitis (AD) is a chronic inflammatory skin disease with persistent itching, which impairs quality of life (QoL). Although various conventional treatments for AD exist, patients with AD often seek complementary and alternative therapies when conventional therapy has failed to relieve their AD symptoms or has had adverse effects. Acupuncture treatment may relieve AD symptoms, but controlled trials are needed to confirm this. Following our pilot study, which found that acupuncture treatment improves AD symptoms in mild-to-moderate AD patients, we will assess the effect of acupuncture treatment for symptom relief of AD using a trial with a complemented protocol. This is a two-arm, randomized, participant- and assessor-blinded, sham-controlled trial. A total of 36 mild-to-moderate AD patients will be randomly assigned in a 1:1 ratio to receive eight sessions twice weekly of either verum acupuncture (VA) or nonpenetrating sham acupuncture (SA) over four weeks. The primary outcome measured will be the change in the total Scoring Atopic Dermatitis (SCORAD) score. Secondary outcomes will be (1) changes in AD symptoms, QoL, dyspepsia symptoms, and electroencephalography (EEG) between baseline and week 4 and (2) changes in AD symptoms and QoL at baseline and at weeks 2, 4, and 8. This study will assess acupuncture treatment for the alleviation of AD symptoms in patients with mild-to-moderate AD. This clinical trial gas been registered in Korean Clinical Trial Registry (registration number: KCT0002796; date of registration: April 13, 2018).

Individual Differences in Responsiveness to Acupuncture: An Exploratory Survey of Practitioner Opinion

Background: Previous research has considered the impact of personal and situational factors on treatment responses. This article documents the first phase of a four-stage project on patient characteristics that may influence responsiveness to acupuncture treatment, reporting results from an exploratory practitioner survey. Methods: Acupuncture practitioners from various medical professions were recruited through professional organisations to complete an online survey about their demographics and attitudes as well as 60 questions on specific factors that might influence treatment. They gave categorical (“Yes”, “No”, and “Don’t know”) and free-text responses. Quantitative and qualitative (thematic) analyses were then conducted. Results: There were more affirmative than negative or uncertain responses overall. Certain characteristics, including ability to relax, exercise and diet, were most often considered relevant. Younger and male practitioners were more likely to respond negatively. Limited support was found for groupings between characteristics. Qualitative data provide explanatory depth. Response fatigue was evident over the course of the survey. Conclusions: Targeting and reminders may benefit uptake when conducting survey research. Practitioner characteristics influence their appreciation of patient characteristics. Factors consistently viewed as important included ability to relax, exercise and diet. Acupuncture practitioners may benefit from additional training in certain areas. Surveys may produce more informative results if reduced in length and complexity.