在瓣周漏的半月瓣病变中，舒张期壁面切应力升高。
Elevated diastolic wall shear stress in regurgitant semilunar valvular lesions.
机构信息
Pediatric Cardiology and Congenital Heart Disease, German Heart Center at Technical University of Munich, Munich, Germany.
Department of Cardiology, Faculty of Medicine, Alexandria University, Alexandria, Egypt.
出版信息
J Magn Reson Imaging. 2019 Sep;50(3):763-770. doi: 10.1002/jmri.26680. Epub 2019 Feb 4.
BACKGROUND
Alterations in wall shear stress (WSS) assessed using 4D flow MRI have been shown to play a role in various vascular pathologies, such as bicuspid aortic valve aortopathy. Most studies have focused on systolic WSS, whereas altered diastolic hemodynamics in regurgitant semilunar valvular lesions have not so far been well characterized.
PURPOSE
To investigate diastolic WSS in aortic and pulmonary regurgitation.
STUDY TYPE
Retrospective data analysis.
POPULATION
Thirty tetralogy of Fallot patients, 19 bicuspid aortic valve patients, 11 healthy volunteers.
FIELD STRENGTH/SEQUENCE: 5 T, 3D time-resolved phase-contrast MRI with 3D velocity encoding.
ASSESSMENT
Estimation of WSS and its axial and circumferential vector components along cardiac cycle timeframes in the proximal main pulmonary artery in pulmonary regurgitation (PR) and in the proximal ascending aorta in aortic regurgitation (AR) as well as in healthy volunteers.
STATISTICAL TESTS
Wilcoxon matched pairs test was used for intra-group comparisons and Mann-Whitney test for intergroup comparisons. Correlations were assessed using Spearman correlation.
RESULTS
WSS along the entire cardiac cycle was higher in PR and AR in comparison with controls (mean WSS 0.381 ± 0.070 vs. 0.220 ± 0.018, P < 0.0001; 0.361 ± 0.099 vs. 0.212 ± 0.030, P < 0.0001; respectively). Peak diastolic WSS was significantly higher than the mean WSS in AR and PR (P < 0.0001-0.005). The severity of PR correlated with the peak diastolic axial WSS (Spearman's r = 0.454, P = 0.018), whereas the severity of AR correlated with both peak systolic and diastolic tangential WSS (Spearman's r = 0.458, P = 0.049; r = 0.539, P = 0.017, respectively).
DATA CONCLUSION
Elevated diastolic WSS is a component of the altered flow hemodynamics in AR and PR. This may give more insight into the pathophysiologic role of WSS in vascular remodeling in AR and PR.
LEVEL OF EVIDENCE
4 Technical Efficacy Stage: 1 J. Magn. Reson. Imaging 2019;50:763-770.
背景
使用 4D 流 MRI 评估的壁切应力 (WSS) 改变已被证明在各种血管病变中起作用，例如二叶式主动脉瓣主动脉瓣病变。大多数研究都集中在收缩期 WSS 上，而目前尚未很好地描述反流性半月瓣病变的舒张期血液动力学改变。
目的
研究主动脉瓣和肺动脉瓣反流中的舒张期 WSS。
研究类型
回顾性数据分析。
人群
30 例法洛四联症患者，19 例二叶式主动脉瓣患者，11 例健康志愿者。
场强/序列：5T，3D 时间分辨相位对比 MRI 与 3D 速度编码。
评估
在肺动脉瓣反流 (PR) 中的近端主肺动脉和主动脉瓣反流 (AR) 中的近端升主动脉以及健康志愿者中沿心动周期时间帧估算 WSS 及其轴向和周向矢量分量。
统计检验
采用 Wilcoxon 配对检验进行组内比较，Mann-Whitney 检验进行组间比较。使用 Spearman 相关评估相关性。
结果
与对照组相比，PR 和 AR 中的整个心动周期 WSS 均升高（平均 WSS 0.381±0.070 比 0.220±0.018，P<0.0001；0.361±0.099 比 0.212±0.030，P<0.0001；分别）。AR 和 PR 中的舒张期峰值 WSS 明显高于平均 WSS（P<0.0001-0.005）。PR 的严重程度与舒张期轴向峰值 WSS 相关（Spearman's r=0.454，P=0.018），而 AR 的严重程度与收缩期和舒张期切向峰值 WSS 均相关（Spearman's r=0.458，P=0.049；r=0.539，P=0.017，分别）。
数据结论
升高的舒张期 WSS 是 AR 和 PR 中血流动力学改变的一个组成部分。这可能更深入地了解 WSS 在 AR 和 PR 中血管重塑中的病理生理作用。
证据水平
4 技术功效阶段：1 J. Magn. Reson. Imaging 2019;50:763-770.
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