Influence of Frightening Audio Frequency based on Regulation of ANS by Emotion on Heart Rate and Heart Rate Variability

Objective To investigate the impact of frightening audio frequency on heart rate and its variability.Methods Seventy healthy volunteers were recruited and divided into two groups with 35 in each according to random number table.Volunteers in group 1 received neutral audio stimulation and those in group 2 received frightening audio stimulation.The heart rate and its variability of each subject were recorded during the stimulation through Actiheart device.Results Compared with group 1,in group 2 the root mean square of successive differences(RMSSD) was lower((37.5±14.7) ms vs.(53.8±30.3) ms),the heart rate was higher((70.2±8.1) /min vs.(65.2±8.2) /min),and the ratio of low frequency over high frequency(LF/HF)((1.52±0.96) vs.(1.03±0.58)) increased,the differences were statistically significant(P0.05).Conclusion The fright emotion could result in the inhibition of vagal activity and produce a sympathetic dominance,and thus reduce RMSSD,increase heart rate and LF/HF.