title: Systemic vascular resistance is increased and associated with accelerated arterial stiffening change in patients with chronic cervical spinal cord injury.
abstract: BACKGROUND
  Despite of stiffening change of conduit arteries, how total peripheral resistance (TPR) is adapted to chronic spinal cord injury (SCI) remains unclear.
  
  
  OBJECTIVE
  To investigate how chronic cervical SCI influences hemodynamic characteristics
  
  
  METHODS
  Cross-sectional, case-control study.
  
  
  METHODS
  Rehabilitation department in the tertiary medical center.
  
  
  METHODS
  Twenty-one male patients with traumatic SCI resulting from cervical spine fracture were recruited. The injury occurred three to 289 months (46 months in average) previously. Twenty-one healthy male participants with matched age and body mass index were enrolled as control group.
  
  
  METHODS
  The subjects were asked to maintain supine rest (SR) and then head-up tilt (HUT) at 60 degree for five minutes, respectively. A novel noninvasive bio-reactance device was employed to measure cardiac hemodynamics, whereas heart rate variability was used to determine cardiac autonomic activity. Additionally, the digital volume pulse analysis was applied to calculate arterial stiffness index (SI) and arteriolar reflection index (RI).
  
  
  RESULTS
  SCI patients revealed less stroke volume and cardiac output (CO), as well as, greater total peripheral resistance (TPR) and SI during SR than normal subjects did. Moreover, the positive correlation between TPR and SI was observed in SCI patients rather than normal subjects. In SCI patients, HUT (1) markedly decreased TPR while CO and cardio-acceleration responses remained intact and (2) decreased HF power value but failed to change LF/HF ratio. Furthermore, the degree of orthostatic hypotension was correlated with the TPRHUT/TPRSR ratio but not the COHUT/COSR ratio.
  
  
  CONCLUSIONS
  Chronic cervical SCI leads to a progressively accelerated increase in vascular stiffness, which is associated with increase in systemic vascular resistance. Furthermore, the cervical SCI-related orthostatic hypotension lies in the impairment of vasoconstriction without cardiac dysfunction. Clinical Rehabilitation Impact. SI, rather than blood pressure, reflects not only cardiovascular risk but also TPR in chronic cervical SCI.
authors: Department of Physical Medicine and Rehabilitation, Chang Gung Memorial Hospital, Tao-Yuan, Taiwan.
authors: S C
authors: SC
authors: Huang
authors: A
authors: A
authors: May-Kuen Wong
authors: H Y
authors: HY
authors: Lien
authors: S
authors: S
authors: Fuk-Tan Tang
authors: T C
authors: TC
authors: Fu
authors: Y
authors: Y
authors: Lin
authors: J S
authors: JS
authors: Wang
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D000886:Anthropometry; D016022:Case-Control Studies; D002908:Chronic Disease; D003430:Cross-Sectional Studies; D018450:Disease Progression; D005500:Follow-Up Studies; D006339:Heart Rate / Q000502:physiology; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D007024:Hypotension, Orthostatic / Q000209:etiology* / Q000503:physiopathology; D015601:Injury Severity Score; D008297:Male; D008875:Middle Aged; D011782:Quadriplegia / Q000150:complications* / Q000175:diagnosis / Q000534:rehabilitation; D012016:Reference Values; D018570:Risk Assessment; D013119:Spinal Cord Injuries / Q000150:complications* / Q000175:diagnosis / Q000534:rehabilitation; D013318:Stroke Volume / Q000502:physiology; D013997:Time Factors; D014655:Vascular Resistance / Q000502:physiology*; D059289:Vascular Stiffness / Q000502:physiology*