Electro-acupuncture at Jianshi (PC5) and Neiguan (PC6) alters heart rate variability (HRV) in frightened volunteers

Background: Fear is one of the most widely studied emotions and is closely associated with the autonomic nervous system (ANS). Previous studies have proven that acupuncture directly impacts the ANS, influences the heart rate (HR) and the heart rate variability (HRV) and exerts other effects. The aim of this study was to explore the effect of Jianshi (PC5) and Neiguan (PC6) electro-acupuncture on HRV during fear-invoking auditory stimulation using an Actiheart ECG recorder. Materials and Methods: Two hundred healthy subjects were recruited. Using a random number table, subjects were grouped for exposure to fear-invoking auditory stimulation (n=40) or neutral auditory stimulation (n=40). After determining that our fear-invoking auditory stimulation produced the fear emotion, the other 120 subjects were similarly divided into an electro-acupuncture (EA group) and a control group that received PC5 and PC6 electro-acupuncture or no intervention. Results: The fear score of the fear-invoking auditory group was significantly higher than that of the neutral auditory group. The EA group showed higher SD, RMSSD, and high frequency (HF) components of HRV than those of the control group. Conclusion: The primary result suggests that PC5 and PC6 electro-acupuncture affects cardiac autonomic neural regulation, mainly via the parasympathetic system, in subjects exposed to fear-invoking auditory stimulation.