| 1. |
- Ahlgren, Åsa Rydén, et al.
(författare)
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Response of the carotid artery longitudinal motion to submaximal physical activity in healthy humans-Marked changes already at low workload
- 2023
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Ingår i: Physiological Reports. - : Wiley. - 2051-817X. ; 11:2
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Tidskriftsartikel (refereegranskat)abstract
- The longitudinal motion of the arterial wall, that is, the displacement of the arterial wall along the artery, parallel to blood flow, is still largely unexplored. The magnitude and nature of putative changes in longitudinal motion of the arterial wall in response to physical activity in humans remain unknown. The aim of this study was therefore to study the longitudinal motion of the carotid artery wall during physical activity in healthy humans. Using in-house developed non-invasive ultrasonic methods, the longitudinal motion of the intima-media complex and the diameter changes of the right common carotid artery (CCA) in 40 healthy volunteers (20 volunteers aged 22-35 years; 20 volunteers aged 55-68 years) were assessed at rest and during submaximal supine bicycle exercise. In a subset of the subjects (n = 18) also intramural shear strain were analyzed. The longitudinal motion of the intima-media complex underwent marked changes in response to physical activity, already at low workload; with most evident a marked increase of the first antegrade displacement (p < 0.001) in early systole. Likewise, the corresponding shear strain also increased significantly (p = 0.004). The increase in longitudinal motion showed significant correlation to increase in blood pressure, but not to blood flow velocity or wall shear stress. In conclusion, physical activity markedly influences the longitudinal motion of the carotid artery wall in healthy humans already at low load. A possible "cushioning" function as well as possible implications for the function of the vasa vasorum, endothelium, and smooth muscle cells and extracellular matrix of the media, are discussed.
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| 2. |
- Sjöstrand, Sandra, et al.
(författare)
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The impact of geometry, intramural friction, and pressure on the antegrade longitudinal motion of the arterial wall : A phantom and finite element study
- 2023
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Ingår i: Physiological Reports. - 2051-817X. ; 11:12
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Tidskriftsartikel (refereegranskat)abstract
- Longitudinal motion of the carotid arterial wall, as measured with ultrasound, has shown promise as an indicator of vascular health. The underlying mechanisms are however not fully understood. We have found, in in vivo studies, that blood pressure has a strong relation to the antegrade longitudinal displacement in early systole. Further, we have identified that a tapered geometry and the intramural friction in-between two parts of a vessel wall influence the longitudinal displacement. We therefore studied the interaction between pressure, vessel geometry and intramural friction, tapered and straight ultrasound phantoms in a paralleled hydraulic bench study and corresponding numerical models. Profound antegrade longitudinal motion was induced in the innermost part of both tapered phantoms and the numerical models, but to a lesser extent when intramural friction was increased in the simulations. Strong correlations (R = 0.82–0.96; p < 1e-3; k = 9.3–14 μm/mmHg) between longitudinal displacement and pulse pressure were found in six of seven regions of interest in tapered phantoms. The motion of the straight phantom and the corresponding numerical model was smaller, on average zero or close to zero. This study demonstrates that tapering of the lumen, low intramural friction, and pressure might be important conducive features to the antegrade longitudinal motion of the arterial wall in vivo.
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| 3. |
- Zhu, Yuxiang, et al.
(författare)
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Comparison of the multi-phasic longitudinal displacement of the left and right common carotid artery in healthy humans
- 2021
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Ingår i: Clinical Physiology and Functional Imaging. - : Wiley. - 1475-0961 .- 1475-097X. ; 41:4, s. 342-354
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Tidskriftsartikel (refereegranskat)abstract
- During the cardiac cycle, there is a multi-phasic bidirectional longitudinal movement (LMov) of the intima-media complex of large arteries, i.e. along the arteries. On the left side the common carotid artery (CCA) arises directly from the aortic arc, whereas on the right side the CCA originate from the innominate artery. The aim of this study was to compare LMov of the left and right CCA of healthy subjects to investigate whether the difference in anatomy are of importance for LMov. The CCA's of 93 healthy subjects were investigated using in-house developed ultrasound methods. Although the basic pattern were the same in the majority of subjects, several phases of LMov were significantly larger on the left side (the first retrograde phase, p=00006; the second antegrade, "returning" phase, p<0.00001; and the rapid retrograde phase of movement at the end of the cardiac cycle, p<0.000001). In contrast, no significant side-difference in the amplitude of the first antegrade movement was seen. The maximal (peak-to-peak) LMov was significantly larger on the left side (p=0.002). The side differences found seem to increase with aging, and may be related to the difference in anatomy, including possible difference in distance to the heart and especially the presence of an extra bifurcation on the right side. Our data provide an important base for the further study of the relation between the longitudinal movement and atherosclerosis and atherosclerotic plaques.
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