Evaluation of Aortic Blood Flow and Wall Shear Stress in Aortic Stenosis and Its Association With Left Ventricular Remodeling.
Evaluation of Aortic Blood Flow and Wall Shear Stress in Aortic Stenosis and Its Association With Left Ventricular Remodeling.
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DOI：
10.1161/circimaging.115.004038
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发表时间：
2016-03
期刊：
影响因子：
--
通讯作者：
Schulz-Menger J
中科院分区：
文献类型：
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作者：
von Knobelsdorff-Brenkenhoff F;Karunaharamoorthy A;Trauzeddel RF;Barker AJ;Blaszczyk E;Markl M;Schulz-Menger J
主动脉瓣狭窄(AS)导致左心室(LV)的应力变化，从而导致广泛的LV重塑。研究目的是描述AS患者升主动脉的血流模式，并确定其与重塑的关系。37例AS患者(轻度14例，中度8例，重度15例，年龄63±13岁)和37例健康对照(年龄60±10岁)进行了4D-Flow磁共振成像。评估升主动脉内螺旋和涡流的形成以及血流偏心率。测量升主动脉的归一化血流距血管中心的位移和峰值收缩期壁切应力(WSS峰值)。根据左心室重量指数(LVMI-I)和左心室重量与舒张末容积的比值(相对室壁质量；RWM)评价左心室重构。AS患者较正常人更易出现明显的螺旋流和涡状流的形成和偏心现象，且AS患者的WSS峰分布不对称且升高。在AS中，主动脉口面积与涡流形成(p=0.0274)、偏心率(p=0.0070)和血流位移(p=0.0021)呈显著负相关。二尖瓣与更强的螺旋(p=0.0098)和涡流形成(p=0.0536)、更高的流量(p=0.11)和更高的WSS峰值(p=0.0926)相关。LVm-I和RWM与主动脉口面积(p=0.0611，p=0.0058)和血流位移(p=0.0058，p=0.0283)显著相关。在这项先导性研究中，AS导致升主动脉血流模式异常和WSS峰值。除主动脉口面积外，归一化血流位移与左心室重构显著相关。
Aortic stenosis (AS) leads to variable stress for the left ventricle (LV) and consequently a broad range of LV remodeling. Study aim was to describe blood flow patterns in the ascending aorta of AS patients and determine their association with remodeling. Thirty-seven patients with AS (14 mild, 8 moderate, 15 severe; age 63±13 years) and 37 healthy controls (age 60±10 years) underwent 4D-flow MRI. Helical and vortical flow formations and flow eccentricity were assessed in the ascending aorta. Normalized flow displacement from the vessel center and peak systolic wall shear stress (WSSpeak) in the ascending aorta were quantified. LV remodeling was assessed based on LV mass index (LVMI-I) and the ratio of LV mass to enddiastolic volume (relative wall mass; RWM). Marked helical and vortical flow formation and eccentricity were more prevalent in patients with AS than in healthy subjects, and AS patients exhibited an asymmetric and elevated distribution of WSSpeak. In AS, aortic orifice area was strongly negatively associated with vortical flow formation (p=0.0274), eccentricity (p=0.0070) and flow displacement (p=0.0021). Bicuspid aortic valve was associated with more intense helical (p=0.0098) and vortical flow formation (p=0.0536), higher flow displacement (p=0.11) and higher WSSpeak (p=0.0926). LVM-I and RWM were significantly associated with aortic orifice area (p=0.0611, p=0.0058) and flow displacement (p=0.0058, p=0.0283). In this pilot study, AS leads to abnormal blood flow pattern and WSSpeak in the ascending aorta. In addition to aortic orifice area, normalized flow displacement was significantly associated with LV remodeling.