Power spectral analysis of heart rate variability in traumatic quadriplegic humans

Inoue, Kazuhiro; Miyake, Shinji; Kumashiro, Masaharu; Ogata, Hiroyuki; Yoshimura, Osamu

doi:10.1152/ajpheart.1990.258.6.h1722

Cited by 58 publications

(43 citation statements)

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“…Note increased LF phase shift (delay) in SCI subject (arrow). (19,29) but has been reported previously (5,20,27,28). The reduced HF power in thoracic SCI subjects suggests reduced vagal tone (33,46,51), which is supported by their higher heart rates.…”

Section: Discussionmentioning

confidence: 62%

Clinical correlates of frequency analyses of cardiovascular control after spinal cord injury

Claydon

Krassioukov²

2008

American Journal of Physiology-Heart and Circulatory Physiology

135

129

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Claydon VE, Krassioukov AV. Clinical correlates of frequency analyses of cardiovascular control after spinal cord injury. Am J Physiol Heart Circ Physiol 294: H668 -H678, 2008. First published November 16, 2007 doi:10.1152/ajpheart.00869.2007.-Spinal cord injury (SCI) has profound effects on cardiovascular autonomic function due to injury to descending autonomic pathways, and cardiovascular diseases are the leading causes of morbidity and mortality after SCI. Evaluation of cardiovascular autonomic dysfunction after SCI and appraisal of simple noninvasive autonomic assessments that are clinically meaningful would be useful to SCI clinicians and researchers. We aimed to assess supine and upright cardiovascular autonomic function from frequency analyses of heart rate and blood pressure variability (HRV and BPV) after SCI. We studied 26 subjects with chronic cervical or thoracic SCI and 17 able-bodied controls. We continuously recorded R-R interval (RRI, by ECG) and beat-to-beat blood pressure (by Finometer) in supine and seated positions. Cardiovascular control was assessed from spectral analysis of RRI and blood pressure time series. Cardiac baroreflex control was assessed from cross-spectral analyses of low-frequency spectra. Supine and upright low-frequency HRV and BPV were reduced in cervical SCI subjects, as were total BPV and HRV. Supine high-frequency HRV was reduced in thoracic SCI subjects. Cardiac baroreflex delay was increased in cervical SCI subjects. Supine frequency domain indexes were correlated with sympathetic skin responses, orthostatic cardiovascular responses, and plasma catecholamine levels. SCI results in reduced sympathetic drive to the heart and vasculature and increased baroreflex delay in cervical SCI subjects and reduced cardiac vagal tone in thoracic SCI subjects. Frequency analyses of autonomic function are related to clinical measures of autonomic control after SCI and provide useful noninvasive clinical tools with which to assess autonomic completeness of injury following SCI. baroreceptor reflex; autonomic nervous system; spectral analysis SPINAL CORD INJURY (SCI) is associated with abnormal cardiovascular control that is related to the level and severity of injury to descending autonomic (sympathetic) pathways (10,15,35). The leading cause of morbidity and mortality in SCI individuals is cardiovascular disease (16,45). This most commonly manifests as neurogenic shock (in acute SCI) (35); supine hypotension (35); orthostatic hypotension (marked decreases in blood pressure in the upright position) (10, 11); autonomic dysreflexia (profound and life-threatening blood pressure increases following afferent stimulation below the lesion) (35); ECG abnormalities and arrhythmia (38), particularly during autonomic dysreflexia (9, 14); and abnormal cardiovascular responses to exercise (8).The severe impact of cardiovascular dysfunction on quality of life after SCI has prompted the search for simple physiological bedside assessments of autonomic function that can easily be performed in the clin...

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Section: Discussionmentioning

confidence: 62%

Clinical correlates of frequency analyses of cardiovascular control after spinal cord injury

Claydon

Krassioukov²

2008

American Journal of Physiology-Heart and Circulatory Physiology

135

129

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“…Decrease in HRV has been found to predict coronary heart disease morbidity and mortality in apparently healthy populations and in patients after an acute coronary event (Akselrod et al 1981). There has been a large scale growth in HRV research in disease states such as diabetic neuropathy (Bernardi et al 1992), cardiac transplantation (Sands et al 1989), myocardial dysfunction (Casolo et al 1989), tetraplegia (Inoue et al 1990), preschool children with short nocturnal sleep (Sampei et al 2006), primary nocturnal enuresis (Dundaroz et al 2001;Unalacak et al 2004), allergic rhinitis (Yokusoglu et al 2007), fetal type Minamata disease (Oka et al 2003), administration of beta blockers (Adamson et al 1994), cardiac resynchronization therapy (Akyol et al 2006), antiarrhytmics (Zuanetti et al 1991) and scopolamine (De Ferrari et al 1993). However, the impact of HRV on clinical decisions is limited.…”

Section: Discussionmentioning

confidence: 99%

Cardiac Autonomic Functions are Altered in Patients with Acute Leukemia, Assessed by Heart Rate Variability

Nevruz

Yokuşoğlu

Uzun

et al. 2007

Tohoku J. Exp. Med.

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“…That both nervous systems moderate PSD levels in the LF band is controversial, however. Some suggest that LF activity is largely due to the SNS and that the ANS balance can be reliably calculated as the ratio of LF to HF (15,20,27). Current prevailing evidence, on the other hand, suggests that the vagal contributions to LF are as significant as those of the sympathetic nervous activities; consequently, the LF-to-HF ratio would be an approximation and not an accurate measure of the ANS balance (7,12,13).…”

mentioning

confidence: 99%

Quantifying cardiac sympathetic and parasympathetic nervous activities using principal dynamic modes analysis of heart rate variability

Zhong

Jan²,

Ju³

et al. 2006

American Journal of Physiology-Heart and Circulatory Physiology

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. Quantifying cardiac sympathetic and parasympathetic nervous activities using principal dynamic modes analysis of heart rate variability. Am J Physiol Heart Circ Physiol 291: H1475-H1483, 2006. First published April 7, 2006 doi:10.1152/ajpheart.00005.2006.-The ratio between low-frequency (LF) and high-frequency (HF) spectral power of heart rate has been used as an approximate index for determining the autonomic nervous system (ANS) balance. An accurate assessment of the ANS balance can only be achieved if clear separation of the dynamics of the sympathetic and parasympathetic nervous activities can be obtained, which is a daunting task because they are nonlinear and have overlapping dynamics. In this study, a promising nonlinear method, termed the principal dynamic mode (PDM) method, is used to separate dynamic components of the sympathetic and parasympathetic nervous activities on the basis of ECG signal, and the results are compared with the power spectral approach to assessing the ANS balance. The PDM analysis based on the 28 subjects consistently resulted in a clear separation of the two nervous systems, which have similar frequency characteristics for parasympathetic and sympathetic activities as those reported in the literature. With the application of atropine, in 13 of 15 supine subjects there was an increase in the sympathetic-to-parasympathetic ratio (SPR) due to a greater decrease of parasympathetic than sympathetic activity (P ϭ 0.003), and all 13 subjects in the upright position had a decrease in SPR due to a greater decrease of sympathetic than parasympathetic activity (P Ͻ 0.001) with the application of propranolol. The LF-to-HF ratio calculated by the power spectral density is less accurate than the PDM because it is not able to separate the dynamics of the parasympathetic and sympathetic nervous systems. The culprit is equivalent decreases in both the sympathetic and parasympathetic activities irrespective of the pharmacological blockades. These findings suggest that the PDM shows promise as a noninvasive and quantitative marker of ANS imbalance, which has been shown to be a factor in many cardiac and stress-related diseases. power spectrum; sympathetic nervous system; parasympathetic nervous system

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Power spectral analysis of heart rate variability in traumatic quadriplegic humans

Cited by 58 publications

References 0 publications

Clinical correlates of frequency analyses of cardiovascular control after spinal cord injury

Clinical correlates of frequency analyses of cardiovascular control after spinal cord injury

Cardiac Autonomic Functions are Altered in Patients with Acute Leukemia, Assessed by Heart Rate Variability

Quantifying cardiac sympathetic and parasympathetic nervous activities using principal dynamic modes analysis of heart rate variability

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