Chivukula Venkat Keshav, Goenezen Sevan, Liu Aiping, Rugonyi Sandra
Department of Mechanical Engineering, University of Washington, Stevens Way, Box 352600, Seattle, WA 98195, USA.
Department of Mechanical Engineering, Texas A&M University, College Station, TX 77840, USA.
J Cardiovasc Dev Dis. 2016 Mar;3(1). doi: 10.3390/jcdd3010001. Epub 2015 Dec 24.
We analyzed heart wall motion and blood flow dynamics in chicken embryos using optical coherence tomography (OCT) imaging and computational fluid dynamics (CFD) embryo-specific modeling. We focused on the heart outflow tract (OFT) region of day 3 embryos, and compared normal (control) conditions to conditions after performing an OFT banding intervention, which alters hemodynamics in the embryonic heart and vasculature. We found that hemodynamics and cardiac wall motion in the OFT are affected by banding in ways that might not be intuitive . In addition to the expected increase in ventricular blood pressure, and increase blood flow velocity and, thus, wall shear stress (WSS) at the band site, the characteristic peristaltic-like motion of the OFT was altered, further affecting flow and WSS. Myocardial contractility, however, was affected only close to the band site due to the physical restriction on wall motion imposed by the band. WSS were heterogeneously distributed in both normal and banded OFTs. Our results show how banding affects cardiac mechanics and can lead, in the future, to a better understanding of mechanisms by which altered blood flow conditions affect cardiac development leading to congenital heart disease.
我们使用光学相干断层扫描（OCT）成像和针对胚胎的计算流体动力学（CFD）建模，分析了鸡胚胎的心脏壁运动和血流动力学。我们重点研究了3日龄胚胎的心脏流出道（OFT）区域，并将正常（对照）情况与进行OFT束带干预后的情况进行了比较，该干预会改变胚胎心脏和血管系统中的血流动力学。我们发现，OFT中的血流动力学和心脏壁运动受束带影响的方式可能并不直观。除了预期的心室血压升高以及血流速度增加，从而导致束带部位的壁面剪应力（WSS）增加外，OFT特有的蠕动样运动也发生了改变，进而影响了血流和WSS。然而，由于束带对壁运动的物理限制，心肌收缩力仅在靠近束带部位受到影响。WSS在正常和束带化的OFT中均呈异质性分布。我们的结果表明了束带如何影响心脏力学，并可能在未来有助于更好地理解血流条件改变影响心脏发育导致先天性心脏病的机制。
