Dynamics of Blood Flows in Aortic Stenosis: Mild, Moderate, and Severe.
Dynamics of Blood Flows in Aortic Stenosis: Mild, Moderate, and Severe.
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动脉狭窄的血流动力学：轻度、中度和重度。
DOI：
10.1097/mat.0000000000001296
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发表时间：
2021-06-01
期刊：
影响因子：
--
通讯作者：
Rosenberg G
中科院分区：
文献类型：
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作者：
Jhun CS;Newswanger R;Cysyk JP;Ponnaluri S;Good B;Manning KB;Rosenberg G
钙化性主动脉狭窄(AS)产生的超生理高切应力可导致止血异常，然而，AS严重程度上的复杂血流与止血异常之间的关系仍不清楚。本研究系统地描述了轻度、中度和重度AS的血流特征。利用粒子图像测速仪(PIV)对具有生理代表性的AS模型进行了一系列的大涡模拟(LES)，峰值生理流动条件为18LPM。时间精确的速度场、跨瓣膜压力梯度和层流粘性和湍流(或雷诺)剪应力(RSSmax)被评估为每种严重程度。轻度、中度和重度AS的峰值流速分别为2.0m/S、4.0m/S和8.0m/S。重度AS的射流速度高度偏斜，速度极高(高达8m/S)，主要通过主动脉后壁到达主动脉弓，但仍携带较高的流速，约为-gt；4m/S，轻度、中度和重度AS的平均层流粘性壁切应力分别约为40pA、100pA和180pA。轻度AS、中度AS和重度AS的RSSmax分别为260、490和2500Pa.这项研究可能提供主动脉狭窄血流改变与获得性von Willebrand综合征和溶血等止血异常之间的联系，从而有助于诊断和治疗时机的选择。
Supraphysiologic high shear stresses created in calcific aortic stenosis (AS) are known to cause hemostatic abnormalities, however, the relationship between the complex blood flows over the severity of AS and hemostatic abnormalities still remains unclear. This study systematically characterized the blood flow in mild, moderate, and severe AS. A series of large eddy simulations (LES) validated by particle image velocimetry (PIV) were performed on physiologically representative AS models with a peak physiological flow condition of 18 LPM. Time-accurate velocity fields, transvalvular pressure gradient, and laminar viscous - and turbulent (or Reynolds) shear stresses (RSSmax) were evaluated for each degree of severity. The peak velocities of mild, moderate, and severe AS were on the order of 2.0 m/s, 4.0 m/s, and 8.0 m/s, respectively. Jet velocity in severe AS was highly skewed with extremely high velocity (as high as 8 m/s) and mainly traveled through the posterior aortic wall up to the aortic arch while still carrying a relatively high velocity, i.e., > 4 m/s. The mean laminar viscous wall shear stresses (WSS) for mild, moderate, and severe AS were on the order of 40 Pa, 100 Pa, and 180 Pa, respectively. The RSSmax were on the order of 260 Pa, 490 Pa, and 2,500 Pa for mild, moderate, and severe AS, respectively. This study may provide a link between altered flows in aortic stenosis and hemostatic abnormalities such as acquired von Willebrand syndrome and hemolysis, thus, help diagnosing and timing of the treatment.