Investigation of heart rate variability and heart rate turbulence in chronic hypotensive hemodialysis patients.

ABSTRACT

BACKGROUND: Sudden cardiac death is the leading cause of cardiac-related death in hemodialysis patients. Hypotensive episodes in pre-, intra-, and post-dialytic periods can present serious clinical challenges that affect a patient's quality of life and prognosis. The aim of the present study was to evaluate cardiac autonomic control and arrhythmogenic risk by analyzing 24-h heart rate variability (HRV) and heart rate turbulence (HRT) in hypotensive hemodialysis patients. METHODS: A total of 79 patients on maintenance hemodialysis treatment, 39 normotensive and 40 with frequent hypotension episodes during non-dialysis periods, were included in the study. Dialysis-free periods were recorded with a 24-h Holter rhythm and ambulatory blood pressure monitor device. The time-domain parameters of HRV and HRT, including turbulence onset (TO) and turbulence slope (TS), were calculated. RESULTS: Values for SDNN (105.5 ± 7.02, 127.6 ± 6.2 p < 0.001), SDANN (95.1 ± 5.9, 111.8 ± 5.01 p < 0.001), and SDNN index (50.04 ± 2.7, 55.6 ± 3.7 p = 0.03), in the hypotensive group were significantly lower than in the normotensive group, respectively. Values for RMSSD (26.5 ± 2.5, 27.3 ± 2.7 p = 0.178), pNN50 (17 ± 1.7, 55.6 ± 3.7 p = 0.03), and TI (35.1 ± 3.1, 34.7 ± 2.6 p = 0.542) in both groups were not significantly different; however, there was a significant difference between HRT parameters, TO (- 1.8 ± 0.37, - 2.4 ± 0.39 p < 0.001) and TS (6.9 ± 0.71, 8.2 ± 0.97 p < 0.001), respectively, hypotensive and normotensive group. CONCLUSION: Dialysis patients that experience frequent hypotensive episodes may also undergo significant changes in HRT and HRV which may be indicative of serious cardiac sequela. Thus, in such cases, a complete cardiologic evaluation is warranted.