Reproducibility of heart rate variability and blood pressure variability in individuals with spinal cord injury

Ditor, David S.; Kamath, M.V.; MacDonald, Maureen J.; Bugaresti, J; McCartney, Neil; Hicks, Audrey L.

doi:10.1007/s10286-005-0293-4

Cited by 46 publications

(38 citation statements)

References 34 publications

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“…Further, although the HF band did not significantly differ between the groups, a trend toward a reduction in this band in the P group was observed. As a result, this decrease in all frequency bands is reflected in a significant reduction in the total power of the spectrum, similar to the findings obtained by Uhlir et al 8 and Ditor et al 23 Regarding the nonlinear analysis, we obtained significant differences only in SD1 and SD2 but not in DFA1, DFA2 or sampen. DFA is a measure of roughness in the time series and predicts fatal cardiovascular events in various populations.…”

Section: Discussionsupporting

confidence: 91%

Heart rate variability in individuals with thoracic spinal cord injury

et al. 2014

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Study design: Cross-sectional study. Objectives: The main goal of our study was to explore the differences in heart rate variability (HRV) while sitting between able-bodied (AB) participants and paraplegic (P) individuals. Setting: The study was conducted in the Physical Therapy department and the Physical Education and Sports department of the University of Valencia and Vall d'Hebrón Hospital. Methods: To record the HRV, a 1000-Hz Suunto Oy t6 heart rate monitor was used. The data were analyzed in the temporal and frequency domains, and nonlinear analysis was performed as well. Results: We found significant differences between P and AB participants in SDNN: t(76) = 2.81, Po0.01; root mean squared of the difference of successive RR intervals: t(76) = 2.35, Po0.05; very low frequency: t(76) = 2.97, Po0.01; low frequency: t(41.06) = 2.33, Po0.05; total power of the spectrum: t(45.74) = 2.57, Po0.05; SD1: t(76) = 2.35, Po0.05; SD2: t(76) = 2.82, Po0.01. Furthermore, there is a reduced variability in the P participants who adopted a sedentary lifestyle as could be observed in detrended fluctuation1 t(40) = − 2.10; Po0.05. Conclusion: Although individuals in the P group were more active in sports than the AB group, they had an altered HRV when compared with AB individuals. It could be important to develop more intense sports programs to improve cardiac vagal tone, which in turn produces a decrease in work and oxygen consumption of the heart.

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Section: Discussionsupporting

confidence: 91%

Heart rate variability in individuals with thoracic spinal cord injury

et al. 2014

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“…These analyses are particularly useful, because they can be relatively simply performed, require only standard hospital equipment (electrocardiogram and beat-tobeat blood pressure), are noninvasive, and provide largely objective measures of autonomic control. These analyses are correlated with meaningful clinical measures of autonomic function and have been extensively validated in able-bodied individuals (13,46), with preliminary studies in SCI individuals confirming their use as reproducible indexes of autonomic cardiovascular regulation (13). Finally, the use of these measures may also be valuable in clinical trials evaluating changes in autonomic function over time or due to interventions aimed at improving autonomic function after SCI.…”

Section: Discussionmentioning

confidence: 88%

“…Although preliminary studies have shown that this technique is reproducible and reliable in SCI individuals (13), no study has correlated frequency domain indexes of autonomic tone with clinical measures of autonomic dysfunction after SCI. Furthermore, the evaluation of reflex delay using this technique has yet to be performed following SCI, despite the known link between increased baroreflex delay and other disorders of cardiac autonomic function (21,23).…”

mentioning

confidence: 99%

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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“…11 HRV measures in the frequency domain have been shown to be highly reproducible in adults with SCI and therefore represent a potentially valid measure of ANS dysregulation in this population. 13 Research employing HRV as a measure of ANS dysfunction in adults with SCI has found altered fluctuations in autonomic function in response to various activities such as tilt tests, exercise and digestion. 14,15 In comparison with AB controls, reduced sympathetic activity was found in adults with SCI, with no differences found for parasympathetic activity.…”

Section: Introductionmentioning

confidence: 99%

Influence of neurological lesion level on heart rate variability and fatigue in adults with spinal cord injury

et al. 2015

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Study design: Group cohort design. Objectives: To determine the influence of spinal cord injury (SCI) and neurological level on heart rate variability (HRV) and associations with fatigue. Setting: SCI rehabilitation outpatient and community settings in New South Wales, Australia. Methods: Participants included 45 adults with SCI living in the community and 44 able-bodied controls. Socio-demographic, neurological injury, psychological, HRV and eye blink variables were assessed. Multivariate analysis of variance and post hoc protected t-tests were used to determine differences in HRV and fatigue as a function of the neurological level. Pearson's correlation analysis was used to determine the relationships between these factors. Results: Participants with SCI had significantly reduced sympathetic activity. Those with tetraplegia had lowered sympathetic activity compared with those with paraplegia and able-bodied controls. Neither were differences in parasympathetic activity found between groups nor were there any significant differences found for the time domain or non-linear domains. Higher levels of fatigue were found in the SCI sample, and participants with tetraplegia had higher fatigue levels compared with those with paraplegia. Fatigued participants were more likely to have altered autonomic function--that is, reduced sympathetic activity. Conclusions: Higher levels of neurological impairment in people with SCI are more likely to result in disordered cardiovascular control involving reduced sympathetic activity, whereas elevated fatigue was found to be associated with increased sympathetic dysfunction. Findings highlight the need to address risks associated with this dysfunction, such as improved HRV and fatigue screening for people with SCI and improved education on cardiovascular risk factors.

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Reproducibility of heart rate variability and blood pressure variability in individuals with spinal cord injury

Cited by 46 publications

References 34 publications

Heart rate variability in individuals with thoracic spinal cord injury

Heart rate variability in individuals with thoracic spinal cord injury

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

Influence of neurological lesion level on heart rate variability and fatigue in adults with spinal cord injury

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