Passive leg movement‐induced hyperaemia with a spinal cord lesion: evidence of preserved vascular function. (5th November 2013)

• Record Type: Journal Article
• Authors: Venturelli, M.; Amann, M.; Layec, G.; McDaniel, J.; Trinity, J. D.; Fjeldstad, A. S.; Ives, S. J.; Yonnet, G.; Richardson, R. S.
• Is Part Of: Acta physiologica. Volume 210:Number 2(2014:Feb.)
• Page Start: 429
• Page End: 439
• Publication Date: 2013-11-05
• Subjects: Physiology -- Periodicals; Physiology -- Research -- Periodicals; 612
• DOI: 10.1111/apha.12173
• Languages: English
• ISSNs: 1748-1708

Abstract

<abstract abstract-type="main" id="apha12173-abs-0001"> <title>Abstract</title> <sec id="apha12173-sec-0001" sec-type="section"> <p>A spinal cord injury (SCI) clearly results in greater cardiovascular risk; however, accompanying changes in peripheral vascular structure below the lesion mean that the real impact of a SCI on vascular function is unclear.</p> </sec> <sec id="apha12173-sec-0002" sec-type="section"> <title>Aim</title> <p>Therefore, utilizing passive leg movement‐induced (PLM) hyperaemia, an index of nitric oxide (NO)‐dependent vascular function and the central hemodynamic response to this intervention, we studied eight individuals with a SCI and eight age‐matched controls (CTRL).</p> </sec> <sec id="apha12173-sec-0003" sec-type="section"> <title>Methods</title> <p>Specifically, we assessed heart rate (HR), stroke volume (SV), cardiac output (CO), mean arterial pressure (MAP), leg blood flow (LBF) and thigh composition.</p> </sec> <sec id="apha12173-sec-0004" sec-type="section"> <title>Results</title> <p>In CTRL, passive movement transiently decreased MAP and increased HR and CO from baseline by 2.5 ± 1 mmHg, 7 ± 2 bpm and 0.5 ± 0.1 L min<sup>−1</sup> respectively. In SCI, HR and CO responses were unidentifiable. LBF increased to a greater extent in CTRL (515 ± 41 ∆mL min<sup>−1</sup>) compared with SCI, (126 ± 25 ∆mL min<sup>−1</sup>) (<italic>P</italic> < 0.05). There was a strong relationship between ∆LBF and thigh muscle volume (<italic>r</italic> = 0.95). After normalizing ∆LBF for this strong relationship (∆LBF/muscle volume), there was evidence of preserved vascular function in SCI (CTRL: 120 ± 9; SCI 104 ± 11 mL min<sup>−1</sup> L<sup>−1</sup>). A comparison of ∆LBF in the passively moved and stationary leg, to partition the contribution of the blood flow response, implied that 35% of the hyperaemia resulted from cardioacceleration in the CTRL, whereas all the hyperaemia appeared peripheral in origin in the SCI.</p> </sec> <sec id="apha12173-sec-0005" sec-type="section"> <title>Conclusion</title> <p>Thus, utilizing PLM‐induced hyperaemia as marker of vascular function, it is evident that peripheral vascular impairment is not an obligatory accompaniment to a SCI.</p> </sec> </abstract>