Keywords:
Cardiac, MR physics, Molecular imaging, Echocardiography, Echocardiography (transoesophageal), MR, Computer Applications-3D, Comparative studies, Computer Applications-Detection, diagnosis, Blood, Image verification, Pathology
Authors:
M. Karvandi, S. A. Hassantash, S. Ranjbar; Tehran/IR
Purpose
Modifications in diastolic function occur in a broad range of cardiovascular diseases and there is an increasing evidence that abnormalities in left ventricular function may contribute significantly to the symptomatology.
The flow inside the left ventricle duringthe diastole is here investigated by numerical solution of the Navier–Stokes equations under the axisymmetric assumption.
The equation are written in a body-fitted,
movingprolate spheroid,
system of coordinates and solved usinga fractional step method.
The system is forced by a given volume time-law derived from clinical data,
and varying the two-degrees-of-freedom ventricle geometry on the basis of a simple model.
The solution under healthy conditions is analysed in terms of vorticity dynamics,
showing that the flow field is characterised by the presence of a vortex wake; it is attached to the mitral valve duringthe acceleratingphase of the E-wave,
and it detaches and translate towards the ventricle apex afterwards.
The flow evolution is discussed,
results are also reported as an M-mode representation of colour-coded Doppler velocity maps.
So demonstration of blood flow direction inside cardiac chambers can provide valuable information in normal subjects and pathologic cardiac processes.
In this project we have attempted to define blood flow pattern in left ventricular dilated cardiomyopathy.
Ranjbar S.
et al.
(2013) recently developed the first novel left ventricular myocardial model mathematically based on echocardiography,
by MATLAB software and LSDYNA software in normal subjects,
which dynamic orientation contraction (through the cardiac cycle) of every individual myocardial fiber could be created by adding together the sequential steps of the multiple fragmented sectors of that fiber.
The left ventricular myocardial modeling of the heart shows that in normal cases myocardial fibers initiate from the posterior-basal region of the heart,
continues through the left ventricular free wall,
reaches the septum,
loops around the apex,
ascends,
and ends at the superior-anterior edge of left ventricle.
In the presence of the left ventricular dilation,
papillary muscles away from each other and the left ventrile is like a sphere (Figure 1,2,3 and 4)