Computational Fluid Dynamic Analysis Of Functional Single Ventricle

Functional single ventricle(FSV)encompasses a group of severe congenital cyanotic heart diseases.The confused malformation and abnormal movement makes the intraventricular fluid dynamics complicated,resulting in additional energy loss,along with the volume and pressure overload,leading to heart failure.To quantitatively analyze the characteristics of intraventricular flow and pressure is critical before and after operation.Computational Fluid Dynamics(CFD)provides a new method on mapping the details of the flow.A series of continuous images acquired by 3D echocardiography were used to reconstruct 3D models of patient-specific ventricle by medical imaging software,Materialise?-Mimics 18.0.The commercial software,ANSYS?-ICEM 14.5,was used to generate mixed grids and velocities of the inlet and outlet as boundary conditions was obtained by 2D echocardiography.ANSYS?-FLUENT was used for simulation.The results matched well with clinical data(P>0.05).A large,counterclockwise vortex appeared and persisted in the left ventricle during periods of diastole.A smaller vortex was formed at the outflow tract.A vortex ring was found in the base region downstream of the mitral orifice.The vortexes vanished during systolic period.In FSV,end diastolic volume,end systolic volume,stroke volume,sphericity index of dominate ventricular chamber and area of atrioventricular valve annulus were larger than those of normal children(P<0.05),the change rate the area of atrioventricular valve annulus was smaller than that of normal children(P<0.01).The ejection fraction of the rudimentary chamber was under the standard of normal ventricle except patient with complete atrioventricular defect.The major vortex inside the ventricle became smaller and rounder and located closer to the atrioventricular valve annulus and lateral wall(P<0.05).The corner vortex became rounder(P<0.01),and the angle of the vortex ring was larger than that of normal children(P<0.01).In FSV,some corner vortex and vortex ring disappeared.CFD is a new method to visualize the intraventriular fluid dynamics.The systolic and diastolic ventricular function of rudimentary chamber is impaired.Smaller,rounder or disappeared vortex and increased vortex ring angel may illustrate the ventricular dysfunction.