HRV spectrum analysis to observe the changes in ANS caused by sympathectomy and vagotomy

In this study, 14 rats were used and divided into two groups, sympathectomy group (7) and vagotomy group (7). Five experimental conditions were devised, anesthetized, skin incision, neurotomy, skin suture, and recovery. During experiment, ECGs of rats were collected three times at each experimental condition for the duration of 5 minutes. After the application of Berger's series algorithm to ECG raw data, HRV spectrum was obtained via FFT. Two peak values representing autonomic nervous system status, HF and LF, were used to extract the parameter, HF/LF ratio. Results showed that HF/LF values were increased for the sympathectomy group and decreased for the vagotomy group. It implies that the variations in HF/LF components exhibit the information for the classification of ANS function quantitatively.