NUMERICAL ANALYSIS OF THE EFFECT OF THE INNER STRUCTURE OF LEFT VENTRICLE ON THE BLOOD FLOW FIELD: EFFECT OF THE NUMBER OF TRABECULAE CARNEAE STRUCTURES
Tomomi Yamada1,2, Toshiyuki Hayase1, Suguru Miyauchi1
1Tohoku University, Japan;
2Graduate School of Biomedical Engineering, Australia;
Myocardial and cerebral infarctions are representative ischemia-related diseases, but the sites of thrombus formation have not been well identified. In previous studies of the left ventricle, internal structures were omitted, assuming a smooth inner wall surface. However, there are complicated internal structures such as papillary muscles and trabeculae carneae (TC) on the inner wall of a real left ventricle. Thrombus formulation in the left ventricle has not been investigated due to fast blood flow, but the blood flow can be stagnated by the effect of inner structures, resulting in thrombus formation. The purpose of this study was to clarify the effect of the inner structures of the left ventricle on the blood flow field by numerical simulation. Especially, the effect of the number of structures represented by TC models was investigated. We performed the simulations by changing the number of TC models and investigated the effects of the inner structures by comparing the results. A time-dependent left ventricle model was made by a reference shape extracted from magnetic resonance images at a reference time and its interpolations during a cardiac cycle. For incorporation of TC models in the calculation model, a simple cosinusoidal convex shape was generated by displacing the numerical grid. The mitral and aortic valves were set to open or close in response to the phases of the heart beat for the numerical simulation. We clarified the effect of internal structures on the blood flow by comparing the velocity vectors, wall shear stress and streamline between the results with and without models of various TC structures.