Quest for the Vulnerable Atheroma: Carotid Stenosis and Diametric Strain—A Feasibility Study

Abstract

The Bernoulli effect may result in eruption of a vulnerable carotid atheroma, causing a stroke. We measured electrocardiography (ECG)-registered QRS intra-stenotic blood velocity and atheroma strain dynamics in carotid artery walls using ultrasonic tissue Doppler methods, providing displacement and time resolutions of 0.1 μm and 3.7 ms. Of 22 arteries, 1 had a peak systolic velocity (PSV) >280 cm/s, 4 had PSVs between 165 and 280 cm/s and 17 had PSVs <165 cm/s. Eight arteries with PSVs <65 cm/s and 4 of 9 with PSVs between 65 and 165 cm/s had normal systolic diametric expansion (0% and 7%) and corresponding systolic wall thinning. The remaining 10 arteries had abnormal systolic strain dynamics, 2 with diametric reduction (>−0.05 mm), 2 with extreme wall expansion (>0.1 mm), 2 with extreme wall thinning (>−0.1 mm) and 4 with combinations. Decreases in systolic diameter and/or extreme systolic arterial wall thickening may indicate imminent atheroma rupture.

“Stroke-Stop” Formula: A Tool for Risk Index Determination in Development of Acute Cerebrovascular Disease in Patients with Asymptomatic Internal Carotid Artery Stenosis

“…To provide more objective description, there were developed more detailed classi cations; however, an interobserver agreement was weak and there was observed a low correlation with the histopathological ndings [24,25].…”

The Effect of Kidney Transplantation on Carotid Artery Intima-Media Thickness in End-Stage Renal Disease Patients

“…The present study aimed to investigate changes in C-IMT before and 6 months after hemodialysis or kidney transplantation in ESRD patients. In addition, we evaluated the carotid artery peak systolic velocity as a potential indicator of the atherosclerotic plaque instability [14][15][16]. The results of this study can add to the evidence.…”

In vivo ultrasound assessment of carotid artery walls and plaques

“…Due to the Venturi effect, described by the Bernoulli equation, the increase in local blood flow velocity (kinetic energy) is at the expense of potential energy, i.e. local blood pressure Xu et al 2016). Within the stenosis, the decreased luminal blood pressure in combination with the higher blood pressure within the local vasa vasorum affect the transmural blood pressure gradient, which may even change direction.…”

“…Therefore, plaque deformation may depend on plaque composition, pulse pressure and wave reflections, and the degree of stenosis in combination with the Venturi effect. These pressure dynamics and plaque features may eventually contribute to plaque rupture Xu et al 2016).…”

“…In addition, due to the Venturi effect, an increase of local blood velocity caused by a smaller lumen area at the stenosis is accompanied with a decrease in local blood pressure Xu et al 2016); the transmural blood pressure gradient is reduced or even reversed Xu et al 2016). The pressure wave reflections in combination with the inwards directed transmural blood pressure gradient and plaque composition may lead to plaque deformation, subsequent plaque fissuring, intraplaque hemorrhage, and eventually plaque rupture Xu et al 2016). Since pressure wave reflections play a role in plaque rupture and may be modulated by degree of luminal obstruction and plaque composition, wave reflection parameters might identify plaque vulnerability.…”