THE HEMODYNAMICS OF STROKES

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THE HEMODYNAMICS OF STROKES
External Carotid Artery Internal Car
otid Artery Emboli Common Carotid Artery
Background
Ischemic strokes can result when blood-clots
(emboli), forming in the carotid bifurcation,
break loose and block flow to the brain. It is
hypothesized that turbulence in arteries can
exacerbate or trigger such damaging
events. However, clinically identifying
turbulence in a pulsatile flow is a challenging
problem.
Schematic representation of a carotid bifurcation
and emboli formation
Objective
To determine the influence of turbulence on the
genesis of arterial disease.
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Research Carried Out
Using a physiologically accurate model of the
carotid artery bifurcation and Laser Doppler
velocimetry, turbulent and coherent contributions
to hemodynamic forces during a cardiac pulse are
identified.
Local maximum shear stress at internal carotid
inlet. Shown are coherent (blue) and turbulent
(pink) contributions.
Key Findings
Turbulence occurs sporadically, usually at end of
cardiac pulse (diastole). Turbulence can cause a
10 fold increase in the maximum shear stress on
the blood cells.
Blood velocity at inlet of internal carotid. The
signal (blue) is decomposed into coherent (red)
and turbulent (pink) contributions