Soohoo Elaine, Waldman Lewis K, Trumble Dennis R
Scott Hall 4N003, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA, 15213, USA.
Insilicomed, Inc., 7825 Fay Ave Suite 200, La Jolla, CA, 92037, USA.
Ann Biomed Eng. 2017 Jun;45(6):1434-1448. doi: 10.1007/s10439-017-1812-x. Epub 2017 Mar 2.
Healthy hearts have an inherent twisting motion that is caused by large changes in muscle fiber orientation across the myocardial wall and is believed to help lower wall stress and increase cardiac output. It was demonstrated that applied apical torsion (AAT) of the heart could potentially treat congestive heart failure (CHF) by improving hemodynamic function. We report the results of parametric computational experiments where the effects of using a torsional ventricular assist device (tVAD) to treat CHF were examined using a patient-specific bi-ventricular computational model. We examined the effects on global hemodynamics as the device coverage area (CA) and applied rotation angle (ARA) were varied to determine ideal tVAD design parameters. When compared to a baseline, pretreatment CHF model, increases in ARA resulted in moderate to substantial increases in ejection fraction (EF), peak systolic pressures (PSP) and stroke work (SW) with concomitant decreases in end-systolic volumes (ESV). Increases in device CA resulted in increased hemodynamic function. The simulation representing the most aggressive level of cardiac assist yielded significant increases in left ventricular EF and SW, 49 and 72% respectively. Results with this more realistic computational model reinforce previous studies that have demonstrated the potential of AAT for cardiac assist.
健康的心脏具有一种固有的扭转运动，这种运动是由心肌壁上肌纤维方向的巨大变化引起的，并且被认为有助于降低壁应力和增加心输出量。研究表明，施加于心尖的心脏扭转（AAT）有可能通过改善血流动力学功能来治疗充血性心力衰竭（CHF）。我们报告了参数化计算实验的结果，在该实验中，使用患者特异性双心室计算模型研究了使用扭转式心室辅助装置（tVAD）治疗CHF的效果。我们研究了随着装置覆盖面积（CA）和施加的旋转角度（ARA）的变化对整体血流动力学的影响，以确定理想的tVAD设计参数。与基线期未经治疗的CHF模型相比，ARA的增加导致射血分数（EF）、收缩压峰值（PSP）和每搏功（SW）有中度到显著的增加，同时收缩末期容积（ESV）减少。装置CA的增加导致血流动力学功能增强。代表最积极水平心脏辅助的模拟使左心室EF和SW分别显著增加了49%和72%。这个更现实的计算模型的结果强化了先前的研究，这些研究证明了AAT用于心脏辅助的潜力。
