Age-Related Vascular Changes Affect Turbulence in Aortic Blood Flow

Abstract

Turbulent blood flow is implicated in the pathogenesis of several aortic diseases but the extent and degree of turbulent blood flow in the normal aorta is unknown. We aimed to quantify the extent and degree of turbulece in the normal aorta and to assess whether age impacts the degree of turbulence. 22 young normal males (23.7 ± 3.0 y.o.) and 20 old normal males (70.9 ± 3.5 y.o.) were examined using four dimensional flow magnetic resonance imaging (4D Flow MRI) to quantify the turbulent kinetic energy (TKE), a measure of the intensity of turbulence, in the aorta. All healthy subjects developed turbulent flow in the aorta, with total TKE of 3-19 mJ. The overall degree of turbulence in the entire aorta was similar between the groups, although the old subjects had about 73% more total TKE in the ascending aorta compared to the young subjects (young = 3.7 ± 1.8 mJ, old = 6.4 ± 2.4 mJ, p < 0.001). This increase in ascending aorta TKE in old subjects was associated with age-related dilation of the ascending aorta which increases the volume available for turbulence development. Conversely, age-related dilation of the descending and abdominal aorta decreased the average flow velocity and suppressed the development of turbulence. In conclusion, turbulent blood flow develops in the aorta of normal subjects and is impacted by age-related geometric changes. Non-invasive assessment enables the determination of normal levels of turbulent flow in the aorta which is a prerequisite for understanding the role of turbulence in the pathophysiology of cardiovascular disease.

Influence of Microgravity on Apoptosis in Cells, Tissues, and Other Systems In Vivo and In Vitro

“…In another search of countermeasures to prevent retinal lesions elicited by microgravity, Lulli et al [ 116 ] exploited the antiapoptotic activity of coenzyme Q10 (CoQ10). Previous data have shown that CoQ10, by its ability to hinder mitochondrial depolarisation, effectively inhibits apoptosis of corneal keratocytes subjected to laser-based irradiation [ 117 , 118 ].…”

“…Previous data have shown that CoQ10, by its ability to hinder mitochondrial depolarisation, effectively inhibits apoptosis of corneal keratocytes subjected to laser-based irradiation [ 117 , 118 ]. Furthermore, results from ground experiments showed that CoQ10 prevents simulated microgravity–induced apoptosis and cytoskeleton alterations in human RPE (ARPE-19) cells [ 116 ]. In an ongoing study, ARPE-19 cells treated with or without CoQ10 were subjected to the space environment onboard the ISS for 72 h. The results from this study, including the assessment of the apoptosis rate, cytoskeletal morphology, telomere integrity and length, and the whole sequence analysis of RNA and DNA, are yet to be published.…”

Influence of Shear-Thinning Blood Rheology on the Laminar-Turbulent Transition over a Backward Facing Step

“…This work shows a shear-thinning rheology can explain the delayed transition for whole blood seen in published experimental data, but this delay is not the full story. The results show that, to accurately model transitional blood flow, and so enable the design of advanced cardiovascular devices, it is essential to incorporate the shear-thinning rheology, and to explicitly model the turbulent eddies.Fluids 2020, 5, 57 2 of 27 patients with no pathological diseases [4,5]. 4D MRI flow data indicated an increase in turbulent kinetic energy (TKE) of 73% in the aorta of older patients compared to younger patients which was determined to be related to area dilation of the aorta due to vascular ageing.…”

“…Fluids 2020, 5, 57 2 of 27 patients with no pathological diseases [4,5]. 4D MRI flow data indicated an increase in turbulent kinetic energy (TKE) of 73% in the aorta of older patients compared to younger patients which was determined to be related to area dilation of the aorta due to vascular ageing.…”

Estudo Numérico Da Influência Da Inclinação Da Prótese Valvar Aórtica No Fluxo Sanguíneo Em Aorta Ascendente

“…De acordo com o levantamento bibliográfico realizado nesta tese, a técnica 4D-flow é utilizada para auxiliar a conhecer o desempenho hemodinâmico na aorta nas seguintes circunstâncias: i) após a instalação de uma prótese valvar (Von Knobelsdorff-Brenkenhoff et al, 2014;Collins et al, 2015;Trauzeddel et al, 2016;Van Kesteren et al, 2018); ii) após o procedimento cirúrgico stent-enxerto (V-SARR) (Semaan et al, 2013;Stephens et al, 2015;Keller et al, 2016); iii) na presença da valva aórtica tricúspide saudável ou valva aórtica bicúspide (Von Knobelsdorff-Brenkenhoff et al, 2014;Garcia et al, 2015;Mirabella et al, 2015;Von Spiczak et al, 2015;Ha et al, 2018;Masutani et al, 2018;Raghav et al, 2018;Shen et al, 2018); iv) seguimento da evolução do aneurisma na aorta (Canstein et al, 2008;Callaghan et al, 2015;Collins et al, 2015;Masutani et al, 2018;Shen et al, 2018) e v) caracterização da doença aterosclerótica na aorta (Harloff et al, 2013;Markl et al, 2013).…”