Agata Dróżdż, Agata Kowalewska, Marzena Frołow, Barbara Sitek, Rafał Niżankowski
View Full Paper
Flow mediated dilation, shear rate, endothelialdysfunction, vasodilation, nitric oxide.
Introduction: Flow mediated-dilation (FMD) is a non-
invasive test of endothelial function based on shear stress-
dependent nitric oxide secretion causing vasodilation.
Normalization of FMD to shear stress was previously
proposed. The aim of present study is an examination of
relationship between shear rate and FMD in patients with
hypertension and atherosclerosis in comparison with
Methods: Three groups (11 with essential hypertension,
28 with advanced atherosclerosis and 26 controls) were
examined. Flow mediated dilation after 5-minute cuff
occlusion and post-deflation shear rate were assessed.
Brachial artery diameters and blood velocities were
obtained by means of high-resolution ultrasound machine.
Results: Positive correlations were found between FMD
and shear rate with correlation coefficients depending on
the disease. Statistical significance was found in
atherosclerosis and control groups. Shear rate stimulus is
most effective in healthy controls and least effective in
Conclusions: Post-ischemic shear rate or shear stress
should also be taken into account while evaluating the
endothelial function with vasodilation measurements.