Long Q, Merrifield R, Xu X Y, Kilner P, Firmin D N, G-Z Yang
Brunel Institute for Bioengineering, Brunel University, Uxbridge, Middlesex, UK.
Proc Inst Mech Eng H. 2008 May;222(4):475-85. doi: 10.1243/09544119JEIM310.
A detailed investigation of left ventricle (LV) flow patterns could improve our understanding of the function of the heart and provide further insight into the mechanisms of heart failure. This study presents patient-specific modelling with magnetic resonance imaging (MRI) to investigate LV blood flow patterns in normal subjects. In the study, the prescribed LV wall movements based on the MRI measurements drove the blood flow in and out of the LV in computational fluid dynamics simulation. For the six subjects studied, the simulated LV flow swirls towards the aortic valve and is ejected into the ascending aorta with a vertical flow pattern that follows the left-hand rule. In diastole, the inflow adopts a reasonably straight route (with no significant secondary flow) towards the apex in the rapid filling phase with slight variations in the jet direction between different cases. When the jet reaches about two thirds of the distance from the inflow plane to the apex, the blood flow starts to change direction and swirls towards the apex. In the more slowly filling phase, a centrally located jet is evident with vortices located on both sides of the jet on an anterior-posterior plane that passes through the mitral and aortic valves. In the inferior-superior plane, a main vortex appears for most of the cases in which an anticlockwise vortex appears for three cases and a clockwise vortex occurs for one case. The simulated flow patterns agree well qualitatively with MRI-measured flow fields.
对左心室（LV）血流模式进行详细研究，有助于我们更好地理解心脏功能，并进一步深入了解心力衰竭的机制。本研究采用磁共振成像（MRI）进行患者特异性建模，以研究正常受试者的左心室血流模式。在该研究中，基于MRI测量规定的左心室壁运动，在计算流体动力学模拟中驱动血液流入和流出左心室。对于所研究的六名受试者，模拟的左心室血流朝着主动脉瓣旋转，并以遵循左手定则的垂直流模式射入升主动脉。在舒张期，在快速充盈阶段，流入的血液朝着心尖采用合理的直线路径（无明显二次流），不同病例之间射流方向略有变化。当射流到达从流入平面到心尖距离的约三分之二时，血流开始改变方向并朝着心尖旋转。在充盈较慢的阶段，在穿过二尖瓣和主动脉瓣的前后平面上，位于中心的射流明显，射流两侧有涡流。在上下平面上，大多数情况下会出现一个主涡流，其中三例出现逆时针涡流，一例出现顺时针涡流。模拟的血流模式与MRI测量的流场在定性上吻合良好。
