Introduction: The arterial wall, like a filter, buffers pulsatility of pressure and flow generated by cardiac activity, minimizing mechanical damage to the arterial wall. Development and progression of vascular disease involve changes in the structure, viscosity (V) and elasticity (E) of arteries, the main determinants of arterial wall buffering capacity (BC). Specific changes in V, E and BC of Atheromatous plaques (AP) and the neighbouring wall have not been fully characterized.

Objectives: To characterize V, E and BC of human carotid arteries with AP.

Methods: We selected 7 subjects (63±8 y.o.) with an echography of neck vessels (B mode and doppler, 10 mHz probe) similar baseline clinical and biochemical characteristics and AP in a common carotid artery (CCA). Five consecutive segments of the CCA, targeting the AP were evaluated (S1-S5 from proximal to distal, S3 the middle part of the plaque,S2 and S4 the proximal and distal shoulders). The instantaneous diameter and the signal of carotid pressure, calibrated with the brachial pressure (using a sphygmomanometer), were obtained and carotid Pressure / Diameter ratio, V, E and BC calculated.

Results: AP exhibited changes in V, E and BC. Biomechanical gradients were detected within the AP, being S3 the stiffer region (increased E, less V and BC, p< 0,05)

Conclusion: Carotid atheromatous plaques present characteristic changes in V, E and BC compared to the neighbouring wall (stiffer than weaker). Future studies of changes in plaques V, E, BC and vulnerability according to patient’s clinical condition and plaque geometry and composition are needed.