Background: Alteration of arterial elastic properties is known to occur in patients with arteritis. Velocity vector image (VVI) is a new technology to assess the multi-dimensional regional mechanics in terms of velocity, strain, strain rate and displacement. The aim of this study was to investigate the mechanical properties of common carotid artery using VVI in patients with Takayasu’s arteritis.
Methods: Vascular property of carotid artery was assessed in 12 patients with Takayasu’s arteritis (11 female, mean age 38±10) and 12 healthy age- and sex- matched controls using VVI. Intima-medial thickness, external diameter and internal diameter of both common carotid arteries were measured in the longitudinal plane using B-mode echocardiography. Peak radial systolic velocity, circumferential strain, circumferential strain rate, radial displacement, time to peak radial systolic velocity (Tv), time to peak circumferential strain (Ts), time to peak circumferential strain rate (Tsr) and time to peak radial displacement (Td) of each segment was measured and compared between the two groups.
Results: Velocity, strain, strain rate and displacement were decreased significantly in patients with Takayasu’s arteritis when compared with controls. However, standard deviations (SD) of Tv, Ts, Tsr, and Td were significantly higher in patients with Takayasu’s arteritis when compared with controls, suggesting disturbance of symmetric arterial expansion during systole (p< 0.001). The severity of carotid stenosis was positively correlated with SD of Tv, Ts, Tsr and Td in patients with Takayasu’s arteritis.
Conclusion: In patients with Takayasu’s arteritis, carotid artery showed dyssynchronous arterial expansion during systole when compared with healthy controls. The degree of dyssynchronous expansion was positively correlated with the severity of carotid artery stenosis. Arterial assessment using VVI may represent a new method for quantifying vascular alteration associated with arteritis noninvasively in humans.
|
