Uremic autonomic neuropathy studied by spectral analysis of heart rate

Abstract

Our study indicates that the current opinion of a major parasympathetic damage in chronic uremic patients on hemodialysis has to be modified in favor of a more widespread autonomic dysfunction involving both the sympathetic and parasympathetic pathways.

The Subjective Sleep Quality and Heart Rate Variability in Hemodialysis Patients

“…34 A reduction of HRV in ESRD patients has been demonstrated in some earlier reports, [19][20][21]35 whereas some other groups reported increased LF power. 36 This discrepancy may be related to clinical or methodological differences.…”

“…The reasons for these changes are unexplained but may be suspected due to the fact that the HD patients nearly have abnormal autonomic function. [19][20][21]34 Also, another reason is that autonomic function fluctuates depending on sleep dynamics when non-REM sleep is accompanied by an augmentation of parasympathetic tone with depression of sympathetic activity, and REM sleep shows reverse change. 26,27 The autonomic function is even synchronized with REM/non-REM ultradian sleep rhythm.…”

“…17,18 The spectral analysis of heart rate variability (HRV) has been proven to be a potent, noninvasive, sensitive, and reproducible tool for the diagnosis of cardiovascular autonomic dysfunction in ESRD. [19][20][21] It is well established that HRV can be divided into total power (TP, 0-0.5 Hz), high-frequency power (HF, 0.15-0.40 Hz), low-frequency power (LF, 0.04-0.15 Hz), and very-low-frequency power (VLF, 0.003-0.04 Hz) components. 22 The HF component is equivalent to respiratory sinus arrhythmia and is thought to reflect vagal control of heart rate.…”

Non-Invasive Assessment of the Autonomic Nervous System

“…Signals arising from the kidney appear to mediate sympathetic over-activity that may be the result of circulating uraemia-related toxins, which are present in renal dysfunction and more pronounced in patients with ESRD regardless of effective dialysis treatment. The circulating toxins may produce sustained activation of sympathetic nervous activity through stimulation of renal afferent signals, which has been shown to be irreversible through long-term dialysis [37]. Furthermore, reports have detailed that lesions may occur in both the afferent and efferent limbs of the ANS in conditions of chronic uraemia [37], which may also contribute to renal dysautonomia.…”

“…The circulating toxins may produce sustained activation of sympathetic nervous activity through stimulation of renal afferent signals, which has been shown to be irreversible through long-term dialysis [37]. Furthermore, reports have detailed that lesions may occur in both the afferent and efferent limbs of the ANS in conditions of chronic uraemia [37], which may also contribute to renal dysautonomia.…”