Profound increase in longitudinal displacements of the porcine carotid artery wall can take place independently of wall shear stress: a continuation report.
The mechanisms underlying longitudinal displacements of the arterial wall, that is, displacements of the wall layers along the artery, and the resulting intramural shear strain remain largely unknown. We have already found that these displacements undergo profound changes in response to catecholamines. Wall shear stress, closely related to wall shear rate, represents the viscous drag exerted on the vessel wall by flowing blood. The aim of the work described here was to study possible relations between the wall shear rate and the longitudinal displacements. We investigated the carotid arteries of five anesthetized pigs in different hemodynamic situations using in-house developed non-invasive ultrasound techniques. The study protocol included administration of epinephrine, norepinephrine and β-blockade (metoprolol). No significant correlation between longitudinal displacement of the intima-media complex and wall shear rate was found. This result suggests that one or multiple pulsatile forces other than wall shear stress are also working along arteries, strongly influencing arterial wall behavior.
Clinical Physiology and Nuclear Medicine Unit, Department of Clinical Sciences, Lund University, Malmö, Sweden. Electronic address: Asa.ryden_ahlgren@med.lu.se.
Åsa Rydén
ÅR
Ahlgren
Department of Thoracic Surgery, Skåne University Hospital, Lund University, Lund, Sweden.
Stig
S
Steen
Biomedical Engineering, Faculty of Engineering, LTH, Lund University, Lund, Sweden.
Simon
S
Segstedt
Biomedical Engineering, Faculty of Engineering, LTH, Lund University, Lund, Sweden.
Tobias
T
Erlöv
Biomedical Engineering, Faculty of Engineering, LTH, Lund University, Lund, Sweden.
Kjell
K
Lindström
Department of Thoracic Surgery, Skåne University Hospital, Lund University, Lund, Sweden.
Trygve
T
Sjöberg
Biomedical Engineering, Faculty of Engineering, LTH, Lund University, Lund, Sweden.
Hans W
HW
Persson
Information Engineering Department, University of Florence, Florence, Italy.
Stefano
S
Ricci
Information Engineering Department, University of Florence, Florence, Italy.
Piero
P
Tortoli
Biomedical Engineering, Faculty of Engineering, LTH, Lund University, Lund, Sweden.
Magnus
M
Cinthio
D000818:Animals; D016880:Anisotropy; D050197:Atherosclerosis / Q000000981:diagnostic imaging*; D001783:Blood Flow Velocity / Q000502:physiology; D001794:Blood Pressure / Q000502:physiology; D002339:Carotid Arteries / Q000000981:diagnostic imaging* / Q000502:physiology*; D059168:Carotid Intima-Media Thickness; D009038:Motion; D011673:Pulsatile Flow / Q000502:physiology; D033081:Shear Strength / Q000502:physiology*; D013314:Stress, Mechanical; D013552:Swine; D059289:Vascular Stiffness / Q000502:physiology
Arterial wall; Catecholamines; Epinephrine; Longitudinal movement; Norepinephrine; Wall shear rate; Wall shear stress