What is the clinical evidence from this study?

Study design: RCT. Population: Healthy volunteers (n=24). Intervention: Acupuncture at the auricular branch of the vagus nerve (ABVN) vs. Placebo-acupuncture at the Ma-35 point. Primary outcome: Standard deviation of normal-to-normal intervals (SDNN) in supine position (p=0.012).

June 9, 2020Open Access

Acupuncture at the auricular branch of the vagus nerve enhances heart rate variability in humans: An exploratory study

Key Result

Acupuncture at the auricular branch of the vagus nerve significantly increased overall heart rate variability (SDNN) by approximately 19% and reduced heart rate by 4-6% compared to placebo in healthy young men.

Study Design

Type

RCT (n=24)

Blinding

Single-blind

Randomization

Randomized sequence

Multicenter

Structured PICO

Does acupuncture at the auricular branch of the vagus nerve improve heart rate variability and parasympathetic tone in healthy young men?

Population

24 healthy male subjects aged between 18 and 25 years, free from structural cardiovascular disease (no history of syncope, myocardial infarction, or arrhythmia), diabetes, or autonomic disorders, and taking no medication.

Intervention

Acupuncture of the auricular branch of the vagus nerve (ABVN) located at the inferior concha of the ear, using 0.30 x 13 mm needles.

Comparator

Placebo-acupuncture at the Ma35 point (used to treat pain caused by gonarthrosis) using 0.25 x 25 mm needles, and an additional control measurement without acupuncture.

Outcome

Heart rate and heart rate variability (HRV) parameters including standard deviation of normal-to-normal intervals (SDNN), root mean square of successive R-R interval differences (RMSSD), high frequency (HF), low frequency (LF), and LF/HF ratio.surrogate

Main Result

Absolute Event Rate: 93% vs 78%

p-value: p=0.012

Limitations

Performed only in male subjects, leaving unclear if the results found can be applied in both sexes
Small study population
Exploratory analysis affected by false-positive results owing to multiple testing
HRV represents an indirect estimate of cardiac autonomic function with significant limitations driven by the influence of respiration and changes in heart rate

Abstract

BACKGROUND: Recent animal and human studies have shown antiarrhythmic effects inhibiting inducibility of atrial fibrillation through low-level transcutaneous electrical stimulation at the auricular branch of the vagus nerve (ABVN). OBJECTIVE: The present study investigated effects of acupuncture at the ABVN on the autonomic cardiac nervous system in humans through analysis of heart rate and heart rate variability (HRV) parameters. METHODS: We enrolled 24 healthy male volunteers and compared acupuncture at the ABVN to placebo-acupuncture performed at the Ma-35 point (an acupuncture point used in traditional Chinese medicine to treat pain caused by gonarthrosis). An additional measurement without acupuncture served as control. We analyzed the following heart rate and HRV parameters: standard deviation of normal-to-normal intervals (SDNN), root mean square of successive R-R interval differences (RMSSD), high frequency (HF), low frequency (LF), LF/HF ratio. RESULTS: < .1) induced by auricular acupuncture in favor of vagal tone. No relevant difference was shown between control and placebo group. CONCLUSION: Acupuncture of the region innervated by the ABVN may activate the parasympathetic nervous system, as suggested by reduction in heart rate and increase in SDNN. However, given the lack of clear significant changes in other HRV parameters, this effect seems modest and its evaluation requires further investigation.

Mark Helpful

Bookmark

Relay

View Full Paper