An FSEI approach for the assessment of stenotic aortic valve effects on the left heart hemodynamics

Fluid–structure-electrophysiology interaction (FSEI) deals with (i) the active contraction of the myocardium, (ii) the complex blood motion and (iii) the related deformation of the cardiac tissues. This three-way coupled approach is key for obtaining predictive cardiac information as the tissue kinematics comes as a part of the solution, rather than being imposed as a boundary condition. FSEI is here applied to study the effects induced by aortic valve stenosis on the hemodynamics. This pathology, typically occurring in elderly individuals, is caused by the stiffening of the valve leaflets, thus impairing the valve functioning and reducing the pumping efficiency of the heart. The disease severity is gradually increased within a high-fidelity model for the left heart, while keeping the same geometrical, elastic and electrophysiological properties of the cardiac system, which would be impossible with in-vivo experiments. We observe an increase of the transvalvular pressure drop and of the peak velocity of the systolic jet velocity along with a reduction of the cardiac ejection fraction. Furthermore, a stenotic aortic valve significantly alters the wall shear stresses and their spatial distribution over the aortic arch and valve leaflets, which may induce a remodeling process of the ventricular myocardium. The numerical results from the multi-physics model are fully consistent with the clinical experience, thus further opening the way for computational engineering aided medical diagnostic.