RESUMO
BACKGROUND/AIMS: Heart rate variability (HRV) is regulated by the balance between the sympathetic and parasympathetic tones. HRV can be used to assess the effects of drugs and other interventions on cardiac autonomic tone, including exercise, respiration, metabolic change, and psychological or physical stress. As few studies have examined HRV in end-stage renal disease (ESRD) patients in Korea, we investigated autonomic nervous system activity reflected in HRV in patients on peritoneal dialysis for ESRD. METHODS: We compared the pattern of cardiac sympathetic and parasympathetic activity through time-and frequency-domain analysis of HRV in 20 ESRD patients and 65 hypertensive control subjects using 24-hour Holter monitoring. The patients had been undergoing peritoneal dialysis at the Bongseng Hospital between January 2006 and December 2008. RESULTS: The mean age of the patients and controls was 53.8+/-13.1 and 55.1+/-13.7 years, respectively. In the patient group, all of the time- and frequency-domain HRV measures were reduced compared with the control group, including the HRV index, normalized unit of low-frequency (LF norm), and ratio of low-frequency power to high-frequency power (LF/HF), whereas the normalized unit of high frequency (HF norm) was increased. CONCLUSIONS: Autonomic tone in ESRD patients on peritoneal dialysis is decreased compared with patients with hypertension. The parasympathetic tone in ESRD patients on peritoneal dialysis dominates over the sympathetic tone.