Tang Dalin, Yang Chun, Geva Tal, Gaudette Glenn, Del Nido Pedro J
Worcester Polytechnic Institute, MA 01609, USA.
Comput Model Eng Sci. 2010;56(2):113-130.
Right and left ventricle (RV/LV) combination models with three different patch materials (Dacron scaffold, treated pericardium, and contracting myocardium), two-layer construction, fiber orientation, and active anisotropic material properties were introduced to evaluate the effects of patch materials on RV function. A material-stiffening approach was used to model active heart contraction. Cardiac magnetic resonance (CMR) imaging was performed to acquire patient-specific ventricular geometries and cardiac motion from a patient with severe RV dilatation due to pulmonary regurgitation needing RV remodeling and pulmonary valve replacement operation. Computational models were constructed and solved to obtain RV stroke volume, ejection fraction, patch area variations, and stress/strain data for patch comparisons. Our results indicate that the patch model with contracting myocardium leads to decreased stress level in the patch area, improved RV function and patch area contractility. Maximum Stress-P(1) (maximum principal stress) value at the center of the patch from the Dacron scaffold patch model was 350% higher than that from the other two models. Patch area reduction ratio was 0.3%, 3.1% and 27.4% for Dacron scaffold, pericardium, and contracting myocardium patches, respectively. These findings suggest that the contracting myocardium patch model may lead to improved recovery of RV function in patients with severe chronic pulmonary regurgitation.
引入了具有三种不同补片材料（涤纶支架、处理过的心包和收缩性心肌）、两层结构、纤维取向以及活性各向异性材料特性的右心室和左心室（RV/LV）组合模型，以评估补片材料对右心室功能的影响。采用材料强化方法对心脏的主动收缩进行建模。对一名因肺动脉反流导致严重右心室扩张、需要进行右心室重塑和肺动脉瓣置换手术的患者进行心脏磁共振（CMR）成像，以获取患者特异性的心室几何形状和心脏运动。构建并求解计算模型，以获得右心室每搏输出量、射血分数、补片面积变化以及用于补片比较的应力/应变数据。我们的结果表明，具有收缩性心肌的补片模型可降低补片区域的应力水平，改善右心室功能和补片面积收缩性。涤纶支架补片模型中补片中心的最大应力-P(1)（最大主应力）值比其他两个模型高350%。涤纶支架、心包和收缩性心肌补片的补片面积减少率分别为0.3%、3.1%和27.4%。这些发现表明，收缩性心肌补片模型可能会改善重度慢性肺动脉反流患者右心室功能的恢复。
