Regional and global patterns of annular remodeling in ischemic mitral regurgitation
Regional and global patterns of annular remodeling in ischemic mitral regurgitation
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DOI：
10.1016/j.athoracsur.2007.04.016
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发表时间：
2007-08-01
影响因子：
4.6
通讯作者：
Gorman, Robert C.
中科院分区：
文献类型：
--
作者：
Ryan, Liam P.;Jackson, Benjamin M.;Gorman, Robert C.
背景哺乳动物的二尖瓣环呈马鞍形。实验研究表明，缺血性二尖瓣返流时鞍形消失。然而，无论是整体瓣环重塑的时间模式还是局部瓣环重塑的几何模式都没有被描述。我们试图在绵羊模型中使用实时三维超声心动图来表征这些变化。10只绵羊在基线和后基底心肌梗死后1小时和8周进行实时三维超声心动图检查。在每个时间点测量多个二尖瓣环几何指数以评估局部和整体瓣环重塑。梗死后1小时，总体环高度从5.8 ± 0.5 mm降至4.0 ± 0.4 mm（p < 0.001）而连合间宽度从29.0 ± 1.3 mm增加到35.7 ± 1.7 mm（p = 0.023），导致整体瓣环高度与连合宽度的比值从20.0% +/- 1.6%降至11.2% +/- 0.9%（p < 0.001）。梗死后8周，总体瓣环高度降至3.9 ± 0.2 mm（p < 0.05），而连合间宽度增至40.7 ± 1.5 mm（p < 0.001），导致总体瓣环高度与连合宽度之比进一步降至9.4% ± 0.4%（p < 0.001）。尽管瓣环重塑涉及整个二尖瓣环，但其程度存在区域异质性。在绵羊模型中，在缺血性二尖瓣返流的发展过程中发生显著的整体瓣环扁平化和扩张。局部瓣环重塑是不均匀的，并且不限于后连合或后瓣环。
Background. The mammalian mitral annulus is saddle shaped. Experimental studies have shown that loss of saddle shape occurs in ischemic mitral regurgitation. However, neither the temporal pattern of global annular remodeling nor the geometric pattern of regional annular remodeling has been described. We sought to characterize these changes using real-time three-dimensional echocardiography in an ovine model.Methods. Ten sheep underwent real-time three-dimensional echocardiography at baseline and 1 hour and 8 weeks after posterobasal myocardial infarction. Multiple mitral annular geometric indexes were measured at each time point to assess regional and global annular remodeling.Results. One hour after infarction, global annular height decreased from 5.8 +/- 0.5 mm to 4.0 +/- 0.4 mm ( p < 0.001) while intercommissural width increased from 29.0 +/- 1.3 mm to 35.7 +/- 1.7 mm ( p = 0.023), resulting in a decrease in the global annular height to commissural width ratio from 20.0% +/- 1.6% to 11.2% +/- 0.9% ( p < 0.001). Eight weeks after infarction, global annular height decreased to 3.9 +/- 0.2 mm ( p < 0.05) while intercommissural width increased to 40.7 +/- 1.5 mm ( p < 0.001), resulting in an additional decrease in the global annular height to commissural width ratio to 9.4% +/- 0.4% ( p < 0.001). Although annular remodeling involved the entire mitral annulus, there was regional heterogeneity in its extent.Conclusions. Significant global annular flattening and dilatation occur during the development of ischemic mitral regurgitation in an ovine model. Regional annular remodeling is heterogeneous and is not limited the posterior commissure or the posterior annulus.