Heart rate variability during auricular acupressure at the left sympathetic point on healthy volunteers: a pilot study

INTRODUCTION: This research is a pilot, single-blinded study investigating heart rate variability (HRV) during auricular acupressure at the left sympathetic point (AH7) in healthy volunteers. METHODS: There were 120 healthy volunteers with hemodynamic indexes (heart rate, blood pressure) within normal ranges, randomly divided into two groups AG and SG (in each group having a gender ratio 1:1, aged 20−29), to receive either auricular acupressure using ear seed (AG) or sham method using adhesive patches without seed (SG) at the left sympathetic point while lying in a supine position. Acupressure intervention lasted 25 min, and HRV was recorded by a photoplethysmography device–namely, Kyto HRM-2511B and Elite appliance. RESULTS: Auricular acupressure at the left Sympathetic point (AG) led to a significant reduction in heart rate (HR) (p < 0.05) and a considerable increase in HRV parameters demonstrated by HF (High-frequency power) (p < 0.05), compared to sham auricular acupressure (SG). However, no significant changes in LF (Low-frequency power) and RR (Respiratory rate) (p > 0.05) were observed in both groups during the process. CONCLUSION: These findings suggest that auricular acupressure at the left sympathetic point may activate the parasympathetic nervous system while a healthy person is lying relaxed.