Modelling the Human Cardiac Fluid Mechanics

In the second edition of the article a virtual heart model
simulating the flow in the active left human ventricle and
atrium is presented. Because in vivo myocardium data is not
available, the movement of the active ventricle and its atrium
is given by three-dimensional, time-dependent invivo image data
of a nuclear spin MRI tomograph. The passive part of the virtual
heart model consists of a model aorta and of two-dimensionally
modelled heart valves. As the flow is actively driven by the
ventricle and atrium, a coupling off low and structure is
necessary to take into account the deviation of the aorta and
the closing and opening of the heart valves. This coupling is
replaced by the movement given by MRI tomograph and ultrasonic
Doppler echocardiography, since we focus on the flow simulation
in the left pumping ventricle. The flow simulation is performed
by a validated commercial software package that uses the finite
volume method. The flow resistance of the circulation through
the body is taken into account with a simplified circulation
model. The article shows how the virtual heart model can be used
to predict flow losses and flow structures due to pathological
ventricle contraction defects. It provides as an example the
flow simulation of an unhealthy human ventricle with an
aneurysm. The flow structure and flow losses are considered
before and after surgery.