Electronic versions

  • Zoe K Sarafis
    University of British Columbia
  • Jordan W Squair
    University of British Columbia
  • Otto F Barak
    University of Novi Sad
  • Geoff B Coombs
    University of British Columbia, Okanagan
  • Jan Elaine Soriano
    University of Calgary
  • Kelly A Larkin-Kaiser
    University of Calgary
  • Amanda H X Lee
    University of British Columbia
  • Alex Hansen
    University of Innsbruck
  • Maro Vodopic
    General Hospital Bruneck
  • Rinaldo Romac
    Clinical Hospital Center Split
  • Christopher Grant
    University of Calgary
  • Rebecca Charbonneau
    University of Calgary
  • Tanja Mijacika
    University of Split School of Medicine
  • Andrei V Krassioukov
    University of British Columbia
  • Philip N Ainslie
    University of British Columbia, Okanagan
  • Zeljko Dujic
    University of Split School of Medicine
  • Aaron A Phillips
    University of Calgary

Cervical spinal cord injury (SCI) leads to autonomic cardiovascular dysfunction that underlies the three- to fourfold elevated risk of cardiovascular disease in this population. Reduced common carotid artery (CCA) dilatory responsiveness during the cold-pressor test (CPT) is associated with greater cardiovascular disease risk and progression. The cardiovascular and CCA responses to the CPT may provide insight into cardiovascular autonomic dysfunction and cardiovascular disease risk in individuals with cervical SCI. Here, we used CPT to perturb the autonomic nervous system in 14 individuals with cervical SCI and 12 uninjured controls, while measuring cardiovascular responses and CCA diameter. The CCA diameter responses were 55% impaired in those with SCI compared with uninjured controls (P = 0.019). The CCA flow, velocity, and shear response to CPT were reduced in SCI by 100% (P < 0.001), 113% (P = 0.001), and 125% (P = 0.002), respectively. The association between mean arterial pressure and CCA dilation observed in uninjured individuals (r = 0.54, P = 0.004) was absent in the SCI group (r = 0.22, P = 0.217). Steady-state systolic blood pressure (P = 0.020), heart rate (P = 0.003), and cardiac contractility (P < 0.001) were reduced in those with cervical SCI, whereas total peripheral resistance was increased compared with uninjured controls (P = 0.042). Relative cerebral blood velocity responses to CPT were increased in the SCI group and reduced in controls (middle cerebral artery, P = 0.010; posterior cerebral artery, P = 0.026). The CCA and cardiovascular responsiveness to CPT are impaired in those with cervical SCI.NEW & NOTEWORTHY This is the first study demonstrating that CCA responses during CPT are suppressed in SCI. Specifically, CCA diameter, flow, velocity, and shear rate were reduced. The relationship between changes in MAP and CCA dilatation in response to CPT was absent in individuals with SCI, despite similar cardiovascular activation between SCI and uninjured controls. These findings support the notion of elevated cardiovascular disease risk in SCI and that the cardiovascular responses to environmental stimuli are impaired.

Keywords

  • Humans, Cervical Cord, Cardiovascular Diseases/diagnosis, Carotid Artery, Common, Carotid Arteries, Middle Cerebral Artery, Spinal Cord Injuries/complications, Autonomic Nervous System Diseases
Original languageEnglish
Pages (from-to)H1311-H1322
JournalAmerican Journal of Physiology - Heart and Circulatory Physiology
Volume323
Issue number6
DOIs
Publication statusPublished - 1 Dec 2022
Externally publishedYes
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