Department of Cardiology, National Heart Centre, Singapore.
Am J Physiol Heart Circ Physiol. 2011 May;300(5):H1653-60. doi: 10.1152/ajpheart.00021.2011. Epub 2011 Feb 25.
Surgical ventricular restoration (SVR) was designed to treat patients with aneurysms or large akinetic walls and dilated ventricles. Yet, crucial aspects essential to the efficacy of this procedure like optimal shape and size of the left ventricle (LV) are still debatable. The objective of this study is to quantify the efficacy of SVR based on LV regional shape in terms of curvedness, wall stress, and ventricular systolic function. A total of 40 patients underwent magnetic resonance imaging (MRI) before and after SVR. Both short-axis and long-axis MRI were used to reconstruct end-diastolic and end-systolic three-dimensional LV geometry. The regional shape in terms of surface curvedness, wall thickness, and wall stress indexes were determined for the entire LV. The infarct, border, and remote zones were defined in terms of end-diastolic wall thickness. The LV global systolic function in terms of global ejection fraction, the ratio between stroke work (SW) and end-diastolic volume (SW/EDV), the maximal rate of change of pressure-normalized stress (dσ*/dt(max)), and the regional function in terms of surface area change were examined. The LV end-diastolic and end-systolic volumes were significantly reduced, and global systolic function was improved in ejection fraction, SW/EDV, and dσ*/dt(max). In addition, the end-diastolic and end-systolic stresses in all zones were reduced. Although there was a slight increase in regional curvedness and surface area change in each zone, the change was not significant. Also, while SVR reduced LV wall stress with increased global LV systolic function, regional LV shape and function did not significantly improve.
外科心室修复(SVR)旨在治疗患有动脉瘤或大无运动壁和扩张心室的患者。然而,对于这种手术疗效至关重要的关键方面,如左心室(LV)的最佳形状和大小,仍存在争议。本研究旨在基于 LV 区域形状的曲率、壁应力和心室收缩功能,定量评估 SVR 的疗效。共有 40 例患者在 SVR 前后接受了磁共振成像(MRI)检查。使用短轴和长轴 MRI 重建舒张末期和收缩末期三维 LV 几何形状。确定整个 LV 的表面曲率、壁厚度和壁应力指数的区域形状。根据舒张末期壁厚度定义梗死、边界和远区。根据整体射血分数、每搏功与舒张末期容积的比值(SW/EDV)、压力标准化应力变化率的最大值(dσ*/dt(max))评估 LV 整体收缩功能,并检查表面面积变化的区域功能。LV 舒张末期和收缩末期容积显著减少,射血分数、SW/EDV 和 dσ*/dt(max) 等整体收缩功能得到改善。此外,所有区域的舒张末期和收缩末期压力均降低。尽管每个区域的区域曲率和表面面积变化略有增加,但变化并不显著。此外,虽然 SVR 降低了 LV 壁应力,同时提高了整体 LV 收缩功能,但 LV 区域形状和功能并未显著改善。