Influence of compression aids on baroreflex in patients after cervical spinal cord injury
| Authors | |
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| Year of publication | 2018 |
| Type | Article in Proceedings |
| Conference | Noninvasive methods in cardiology 2018 |
| MU Faculty or unit | |
| Citation | |
| Web | http://www.med.muni.cz/dokumenty/pdf/noninvasive_methods_in_cardiology_2018.pdf |
| Keywords | Cervical spinal cord injury; orthostatic hypotension; baroreflex; compression aids |
| Description | Introduction: Patients after cervical spinal cord injury (cSCI) often suffer from orthostatic hypotension (OH). Although vagal cardiac chronotropic effect is preserved in cSCI, baroreflex vascular tone regulation is impaired due to interrupted sympathetic pathways below the cSCI level. Patients usually use compression aids (CA, e.g. stockings, abdominal corset) to mitigate blood pressure (BP) drop during orthostasis. This study aimed to assess the influence of CA on baroreflex function in cSCI patients during orthostasis. Methods: BP was continuously recorded in 9 cSCI patients during passive orthostasis without and with CA. Beat-to-beat systolic blood pressure (SBP) and inter-beat intervals (IBI) sequences were obtained from continuous non-invasive BP recording. Pulse pressure (PP) was evaluated as a mean of beat-to-beat differences between SBP and diastolic pressures. Closed loop of SBP IBI interaction was mathematically opened by bivariate autoregressive model; causal coherence (a measure of IBI and SBP synchronization) and gain estimating baroreflex sensitivity (BRS) were calculated in baroreflex direction (from SBP to IBI). Results: When CA were applied, coherence and PP were significantly increased as compared to orthostasis without CA (p < 0.05). CA application was also associated with an increase of BRS (borderline significant; p = 0.059). Patients reported less OH symptoms when wearing CA. Conclusion: Use of CA increased venous return and consequently stroke volume expressed as an increase of PP in this study. This probably prevented the baroreflex sensitivity decrease during orthostasis. We suppose that positive influence of CA on blood pressure regulation during orthostasis weakened OH symptoms in cSCI. |
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