Objective To study the change and significance of hemodialysis on heart rate variability(HRV) in patients with end stage of renal dysfunction. Methods A total of 267 patients with end stage of renal dysfunction and 60 normal persons were examined with 24-hour dynamic electrocardiography and their HRV between two groups including before and after hemodialysis were analysed. HRV measurement included standard deviation of normal RR intervals(SDNN)

5-minute average normal RR intervals(SDANN) and so on. Results The HRV of normal persons had obviously changing regularity from day to night. HRV on night was more than that of day. The HRV of patients with end stage renal dysfunction was obviously lower than normal persons and the regularity between day and night has lost

the vagus nerve activity also decreased. These changes were improve after hemodialysis. Conclusions The HRV of patients with end stage of renal dysfunction has obviously change than normal persons group. The vagus nerve activity decreased and the regularity of day to night lost. The hemodialysis can increase the HRV of patients with end stage renal dysfunction and improve heart autonomic function