Background

Right ventricular (RV) remodeling involves changes in size, wall thickness, function, and shape. Previous studies have suggested that regional curvature indices (rCI) may be useful for RV shape analysis. The aim of this study was to establish normal three-dimensional echocardiographic values of rCI in a large group of healthy subjects to facilitate future three-dimensional echocardiographic study of adverse RV remodeling.

Methods

RV endocardial surfaces were reconstructed at end-diastole and end-systole in 245 healthy subjects (mean age, 42 ± 12 years) and analyzed using custom software to calculate mean curvature in six regions: RV inflow tract (RVIT) and RV outflow tract, apex, and body (both divided into free wall and septal regions). Associations with age and gender were studied.

Results

The apical free wall was convex, while the septum (apex and body) was more concave than the body free wall. Septal curvature did not change significantly from end-diastole to end-systole. The RV outflow tract and RVIT became flatter from end-diastole to end-systole. In keeping with the “bellows-like” action of RV contraction, the body free wall became flatter, while the apex free wall changed to a more convex surface. There were no intergender differences in rCI. In older subjects (≥55 years of age), the RV free wall and RV outflow tract were flatter, and from end-diastole to end-systole, the RVIT became less flattened and the apex less pointed. These changes suggest that the right ventricle is stiffer in older subjects, with less dynamic contraction of the RVIT and less bellows-like movement.

Conclusions

This study established normal three-dimensional echocardiographic values for RV rCI, which are needed to further study RV diastolic dysfunction and remodeling with disease.

中文翻译：

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三维超声心动图得出的曲率指标对正常右心室的形态学分析

背景

右心室（RV）重塑涉及尺寸，壁厚，功能和形状的改变。先前的研究表明，区域曲率指数（rCI）可能对RV形状分析有用。这项研究的目的是在一大群健康受试者中建立rCI的正常三维超声心动图值，以促进未来对RV重构不良的三维超声心动图研究。

方法

在245名健康受试者（平均年龄，42±12岁）的舒张末期和收缩末期重建RV心内膜表面，并使用定制软件进行分析以计算六个区域的平均曲率：RV流入道（RVIT）和RV流出道，根尖和身体（均分为游离壁和中隔区域）。研究与年龄和性别的关联。

结果

顶自由壁是凸形的，而隔膜（顶和身体）比自由壁更凹。从舒张末期到收缩末期，中隔曲率没有明显变化。从舒张末期到收缩末期，RV流出道和RVIT变得平坦。与RV收缩的“类似波纹管”作用一致，无身体壁变得更平，而无顶点壁变成了更凸的表面。rCI中没有性别差异。在年龄较大的受试者（≥55岁）中，右室游离壁和右室流出道较平坦，并且从舒张末期到收缩末期，RVIT变得较不平坦，并且根尖也较尖。这些变化表明，老年受试者的右心室较硬，RVIT的动态收缩较少，风箱状运动较少。

结论

这项研究建立了正常的RV rCI三维超声心动图值，这是进一步研究RV舒张功能障碍和疾病重塑所必需的。