A four-dimensional study of the aortic root dynamics
A four-dimensional study of the aortic root dynamics
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DOI：
10.1016/s1010-7940(02)00405-0
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发表时间：
2002-10-01
影响因子：
3.4
通讯作者：
Duran, CMG
中科院分区：
文献类型：
--
作者：
Lansac, E;Lim, HS;Duran, CMG
目的：尽管主动脉根部扩张已得到充分研究，但其变形和生理相关性仍存在争议。三维 (3-D) 声测法 (200 Hz) 使与时间相关的 4-D 研究成为可能。方法：将 15 个声测晶体植入 8 只羊的主动脉根部，每个基部（3 个）、连合部（3 个）、瓦氏窦（3 个）、窦管交界处（3 个）和升主动脉（3 个）。在这种急性开胸模型中，主动脉根部的几何变形与左心室和主动脉压力随时间变化。结果：在心动周期期间，主动脉根部体积增加了平均值的 1 个标准误差 (SEM) 33.7 +/- 2.7%，其中 36.7 +/- 3.3% 发生在射血之前。在基部和连合处等容收缩期间开始扩张，随后（延迟后）是窦管连接处。与此同时，升主动脉面积减少（-2.6 +/- 0.4%）。在射血的前三分之一期间，主动脉根部达到最大扩张，随后体积缓慢、然后快速减小，直到舒张中期。在舒张末期，主动脉根部体积重新扩张 11.3 +/- 2.4%，但每个区域水平的动态变化不同。虽然基底部和连合区重新扩大，但窦管交界区和升主动脉面积不断减少。舒张末期，主动脉根部呈截锥形（基部面积 > 连合面积 51.6 +/- 2.0%）。在收缩期，根变得更加圆柱形（基部面积 > 连合面积 39.2 +/- 2.5%），因为大多数显着变化发生在连合水平（63.7 +/- 3.6%）。结论：主动脉根部扩张在收缩期遵循精确的时间顺序，并变得更加圆柱形——可能是为了最大限度地射血。这些发现可能会刺激主动脉瓣和主动脉根部外科手术采取更符合生理学的方法。 (C) 2002 Elsevier Science B.V. 保留所有权利。
Objective: Although aortic root expansion has been well studied, its deformation and physiologic relevance remain controversial. Three-dimensional (3-D) sonomicrometry (200 Hz) has made time-related 4-D study possible. Methods: Fifteen sonomicrometric crystals were implanted into the aortic root of eight sheep at each base (three), commissures (three), sinuses of Valsalva (three), sinotubular junction (three), and ascending aorta (three). In this acute, open-chest model, the aortic root geometric deformations were time related to left ventricular and aortic pressures. Results: During the cardiac cycle, aortic root volume increased by mean 1 standard error of the mean (SEM) 33.7 +/- 2.7%, with 36.7 +/- 3.3% occurring prior to ejection. Expansion started during isovolumic contraction at the base and commissures followed (after a delay) by the sinotubular junction. At the same time, ascending aorta area decreased (-2.6 +/- 0.4%). During the first third of ejection, the aortic root reached maximal expansion followed by a slow, then late rapid decrease in volume until mid-diastole. During end-diastole, the aortic root volume re-expanded by 11.3 +/- 2.4%, but with different dynamics at each area level. Although the base and commissural areas re-expanded, the sinotubular junction and ascending aorta areas kept decreasing. At end-diastole, the aortic root had a truncated cone shape (base area > commissures area by 51.6 +/- 2.0%). During systole, the root became more cylindrical (base area > commissures area by 39.2 +/- 2.5%) because most of the significant changes occurred at commissural level (63.7 +/- 3.6%). Conclusion: Aortic root expansion follows a precise chronology during systole and becomes more cylindrical - probably to maximize ejection. These findings might stimulate a more physiologic approach to aortic valve and aortic root surgical procedures. (C) 2002 Elsevier Science B.V. All rights reserved.