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Alterations in the rheological artery during rhythmic thigh flow profile in conduit femoral muscle contractions in humans

Osada, T and Rådegran, Göran LU (2005) In Japanese Journal of Physiology 55(1). p.19-28
Abstract
The present study examined the rheological blood velocity profile in the conduit femoral artery during rhythmic muscle contractions at different muscle forces. Eight healthy volunteers performed one-legged, dynamic knee-extensor exercise at work rates of 5, 10, 20, 30, and 40 W at 60 contractions per minute. The time and space-averaged, amplitude-weighted mean ( V-mean) and maximum (V-max) blood flow velocities in the common femoral artery were measured during the cardiosystolic phase (CSP) and cardiodiastolic phase (CDP) by the Doppler ultrasound technique. The V-max /V-mean ratio was used as a flow profile index, in which a ratio of similar to 1 indicates a m m "flat velocity flow profile" and a ratio significantly > 1 indicates a... (More)
The present study examined the rheological blood velocity profile in the conduit femoral artery during rhythmic muscle contractions at different muscle forces. Eight healthy volunteers performed one-legged, dynamic knee-extensor exercise at work rates of 5, 10, 20, 30, and 40 W at 60 contractions per minute. The time and space-averaged, amplitude-weighted mean ( V-mean) and maximum (V-max) blood flow velocities in the common femoral artery were measured during the cardiosystolic phase (CSP) and cardiodiastolic phase (CDP) by the Doppler ultrasound technique. The V-max /V-mean ratio was used as a flow profile index, in which a ratio of similar to 1 indicates a m m "flat velocity flow profile" and a ratio significantly > 1 indicates a "parabolic velocity flow profile ' " At rest, the V-max / V-mean ratio was similar to 1.3 and similar to 1.8 during the CSP and CDP, respectively. The V-max/V-mean ratio was higher (p < 0.01) during the CDP than during the CSP, both at rest and at all work rates. The V-max/V-mean ratio during the CSP was higher Max (p < 0.01) at 30 and 40 W compared to at rest. The V-max/V-mean ratio during the CDP was lower (p < 0.05) at 5 and 10 W compared to at rest. There was a positive linear correlation between blood flow and incremental work rates during both the CSP and CDP, respectively. Thus under resting conditions, the findings indicate a "steeper" parabolic velocity profile during the CDP than during the CSR The velocity profile during the CDP furthermore shifts to being less "steep" during rhythmic muscle contractions at lower intensities, but to being reelevated and normalized as at rest during higher intensities. The "steepness" of the parabolic velocity profile observed during the CSP at rest increased during muscle contraction at higher intensities. In conclusion, the blood velocity in the common femoral artery is parabolic both at rest and during exercise for both the CSP and CDP, indicating the persistence of laminar flow. The occurrence of any temporary slight disturbance or turbulence in the flow at the sight of measurement in the common femoral artery does consequently not induce a persisting "disturbed" and fully flat "plug-like" velocity profile. Instead, the "steepness" of the parabolic velocity profile is only slightly modified, whereby blood flow is not impaired. Thus the blood velocity profile, besides being influenced by the muscle contraction-relaxation induced mechanical "impedance," seems also to be modulated by the cardiac- and blood pressure-phases, consequently influencing the exercise blood flow response. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
rhythmic exercise, maximum and mean blood velocity, exercise hyperemia, rheological blood flow profile, Doppler ultrasound
in
Japanese Journal of Physiology
volume
55
issue
1
pages
19 - 28
publisher
Center for Academic Publications
external identifiers
  • wos:000228487300003
  • pmid:15796786
  • scopus:17644398372
ISSN
0021-521X
DOI
10.2170/jjphysiol.R2074
language
English
LU publication?
yes
id
f4d682aa-ea3c-4a3f-afe3-a4722ef5b733 (old id 245783)
date added to LUP
2007-08-03 16:21:52
date last changed
2017-01-01 06:50:51
@article{f4d682aa-ea3c-4a3f-afe3-a4722ef5b733,
  abstract     = {The present study examined the rheological blood velocity profile in the conduit femoral artery during rhythmic muscle contractions at different muscle forces. Eight healthy volunteers performed one-legged, dynamic knee-extensor exercise at work rates of 5, 10, 20, 30, and 40 W at 60 contractions per minute. The time and space-averaged, amplitude-weighted mean ( V-mean) and maximum (V-max) blood flow velocities in the common femoral artery were measured during the cardiosystolic phase (CSP) and cardiodiastolic phase (CDP) by the Doppler ultrasound technique. The V-max /V-mean ratio was used as a flow profile index, in which a ratio of similar to 1 indicates a m m "flat velocity flow profile" and a ratio significantly &gt; 1 indicates a "parabolic velocity flow profile ' " At rest, the V-max / V-mean ratio was similar to 1.3 and similar to 1.8 during the CSP and CDP, respectively. The V-max/V-mean ratio was higher (p &lt; 0.01) during the CDP than during the CSP, both at rest and at all work rates. The V-max/V-mean ratio during the CSP was higher Max (p &lt; 0.01) at 30 and 40 W compared to at rest. The V-max/V-mean ratio during the CDP was lower (p &lt; 0.05) at 5 and 10 W compared to at rest. There was a positive linear correlation between blood flow and incremental work rates during both the CSP and CDP, respectively. Thus under resting conditions, the findings indicate a "steeper" parabolic velocity profile during the CDP than during the CSR The velocity profile during the CDP furthermore shifts to being less "steep" during rhythmic muscle contractions at lower intensities, but to being reelevated and normalized as at rest during higher intensities. The "steepness" of the parabolic velocity profile observed during the CSP at rest increased during muscle contraction at higher intensities. In conclusion, the blood velocity in the common femoral artery is parabolic both at rest and during exercise for both the CSP and CDP, indicating the persistence of laminar flow. The occurrence of any temporary slight disturbance or turbulence in the flow at the sight of measurement in the common femoral artery does consequently not induce a persisting "disturbed" and fully flat "plug-like" velocity profile. Instead, the "steepness" of the parabolic velocity profile is only slightly modified, whereby blood flow is not impaired. Thus the blood velocity profile, besides being influenced by the muscle contraction-relaxation induced mechanical "impedance," seems also to be modulated by the cardiac- and blood pressure-phases, consequently influencing the exercise blood flow response.},
  author       = {Osada, T and Rådegran, Göran},
  issn         = {0021-521X},
  keyword      = {rhythmic exercise,maximum and mean blood velocity,exercise hyperemia,rheological blood flow profile,Doppler ultrasound},
  language     = {eng},
  number       = {1},
  pages        = {19--28},
  publisher    = {Center for Academic Publications},
  series       = {Japanese Journal of Physiology},
  title        = {Alterations in the rheological artery during rhythmic thigh flow profile in conduit femoral muscle contractions in humans},
  url          = {http://dx.doi.org/10.2170/jjphysiol.R2074},
  volume       = {55},
  year         = {2005},
}