scholarly journals Computer simulation of a blood flow in a left ventricle-aortic arch integrated model

2003 ◽  
Vol 2003.16 (0) ◽  
pp. 289-290
Author(s):  
Masanori Nakamura ◽  
Daisuke Mori ◽  
Shigeo Wada ◽  
Kenichi Tsubota ◽  
Takami Yamaguchi
Author(s):  
Masanori NAKAMURA ◽  
Suguru YOKOSAWA ◽  
Daisuke MORI ◽  
Shigeo WADA ◽  
Kenichi TSUBOTA ◽  
...  

2006 ◽  
Vol 128 (6) ◽  
pp. 837-843 ◽  
Author(s):  
Masanori Nakamura ◽  
Shigeo Wada ◽  
Takami Yamaguchi

To study the effects of intraventricular flow dynamics on the aortic flow, we created an integrated model of the left ventricle and aorta and conducted a computer simulation of diastolic and systolic blood flow within this model. The results demonstrated that the velocity profile at the aortic annulus changed dynamically, and was influenced by the intraventricular flow dynamics. The profile was almost flat in early systole but became nonuniform as systole progressed, and was skewed toward the posterior side in midsystole and toward the anterior side in later systole. At a distance from the aortic annulus, a different velocity profile was induced by the twisting and torsion of the aorta. In the ascending aorta, the fastest flow was initially located in the posteromedial sector, and it moved to the posterior section along the circumference as systole progressed. The nonuniformity of the aortic inflow gave rise to a complex wall shear stress (WSS) distribution in the aorta. A comparison of the WSS distribution obtained in this integrated analysis with that obtained in flow calculations using an isolated aorta model with Poiseuille and flat inlet conditions showed that intraventricular flow affected the WSS distribution in the ascending aorta. These results address the importance of an integrated analysis of flow in the left ventricle and aorta.


2007 ◽  
Vol 55 (S 1) ◽  
Author(s):  
W Schiller ◽  
K Spiegel ◽  
T Schmid ◽  
H Rudorf ◽  
S Flacke ◽  
...  

2007 ◽  
Vol 6 (1) ◽  
pp. 94-96
Author(s):  
V. Ye. Tolpekin ◽  
D. V. Shumakov ◽  
E. K. Gasanov ◽  
R. Sh. Saitgareyev ◽  
A. V. Mukha ◽  
...  

One of the most popular methods of myocardial revascularization is the surgery of coronary arteries. Our research results revealed that adequate myocardial blood flow is provided by hemo-perfusion from the left ventricle to coronary arter-ies.


Author(s):  
Steven W. Day ◽  
James C. McDaniel ◽  
Phillip P. Lemire ◽  
Houston G. Wood

An estimated 150,000 patients in the Western World require heart transplantation every year, while only 4,000 (2.5%) of them actually receive a donor heart [1]. This lack of available donors for heart transplantation has led to a large effort since the 1960s to develop an artificial mechanical heart as an alternative to heart transplant. Most end stage cardiac failures result from cardiac disease or tissue damage of the left ventricle. After this failure, the ventricle is not strong enough to deliver an adequate supply of oxygen to critical organs. A left ventricular assist device (LVAD) is a mechanical pump that does not replace the native heart, but rather works in concert with it. An LVAD can effectively relieve some strain from a native heart, which has been weakened by disease or damage, and increase blood flow supplied to the body to maintain normal physiologic function. The inlet to the LVAD is attached to the native left ventricle, and the output of the assist pump rejoins the output of the native heart at the aorta, as shown in Figure 1. Blood flow from both the aortic valve and the assist pump combine and flow through the body. The clinical effectiveness of LVADs has been demonstrated; however, all of the currently available pumps have a limited life because of either the damage that they cause to blood or their limited mechanical design life.


Author(s):  
Muralidhar Padala ◽  
Ajit P. Yoganathan

The Mitral Valve (MV) is the left atrioventricular valve that controls blood flow between the left atrium and the left ventricle (Fig 1A-B). It has four main components: (i) the mitral annulus — a fibromuscular ring at the base of the left atrium and the ventricle; (ii) two collagenous planar leaflets — anterior and posterior; (iii) web of chordae and (iv) two papillary muscles (PM) that are part of the left ventricle (LV). Normal function of the mitral valve involves a delicate force balance between different components of the valve.


Author(s):  
Ahmad Moghaddaszade-Kermani ◽  
Peter Oshkai ◽  
Afzal Suleman

Mitral-Septal contact has been proven to be the cause of obstruction in the left ventricle with hypertrophic cardiomyopathy (HC). This paper presents a study on the fluid mechanics of obstruction using two-way loosely coupled fluid-structure interaction (FSI) methodology. A parametric model for the geometry of the diseased left ventricular cavity, myocardium and mitral valve has been developed, using the dimensions extracted from magnetic resonance images. The three-element Windkessel model [1] was modified for HC and solved to introduce pressure boundary condition to the aortic aperture in the systolic phase. The FSI algorithm starts at the beginning of systolic phase by applying the left ventricular pressure to the internal surface of the myocardium to contract the muscle. The displacements of the myocardium and mitral leaflets were calculated using the nonlinear finite element hyperelastic model [2] and subsequently transferred to the fluid domain. The fluid mesh was moved accordingly and the Navier-Stokes equations were solved in the laminar regime with the new mesh using the finite volume method. In the next time step, the left ventricular pressure was increased to contract the muscle further and the same procedure was repeated for the fluid solution. The results show that blood flow jet applies a drag force to the mitral leaflets which in turn causes the leaflet to deform toward the septum thus creating a narrow passage and possible obstruction.


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