On the Left Ventricular Vortex Reversal after Mitral Valve Replacement

Abstract

Abstract-The blood flow in the human left ventricle is known to develop a vortical motion that should facilitate the ejection of blood into the primary circulation. This study shows that such a rotary motion can be totally reversed after the implant of a prosthetic valve. This phenomenon, in agreement with clinical observation, appears mostly imputable to the symmetry of the implant. The reversed rotation increases energy dissipation and modifies the pressure distribution with the potential development of new pathologies. The results provide preliminary, physically based, elements for the improvement of surgical procedures or prosthesis.

Asymptotic Model of Fluid–Tissue Interaction for Mitral Valve Dynamics

“…Following the same approach, the outcome of a MV replacement procedure on the LV flow was mimicked by varying the inclinations of the trans-mitral velocity profile. Results showed evidence of a reversal in the main circulatory diastolic flow structure 28,32 previously observed in clinical investigation. 11 In the same way, within an axisymmetric approximation, a previous study analyzed the influence of valvular opening by changing the inlet velocity profile, suggesting that the valve motion influences only the early accelerating phase.…”

“…12,14 The natural and apparently harmonious behavior of the flowing blood modifies in presence of a dysfunctional mitral valve (MV) or by the insertion of prosthetic ones. 21,28 In fact, the vortex formation process is intrinsically connected to the dynamics of the mitral leaflets while they interact with the blood crossing the valve during diastole. However, modeling the dynamics of a natural MV still represents a challenging issue.…”

Comparative numerical study on left ventricular fluid dynamics after dilated cardiomyopathy

“…Kinetic Energy Dissipation: Calculated from the time integral of the rate of kinetic energy (KE) viscous dissipation (Pedrizzetti and Domenichini, 2005;Pedrizzetti et al, 2010) and measures the amount of energy, ΔKE, which is dissipated into heat during the phases of the cycle. Smooth regular flow presents low values of dissipation; whereas high dissipation is associated with a complex flow, possibly turbulent.…”

“…There is an increasing consensus that maladaptive fluid mechanics contributes to cardiac inefficiency and participates in the modulation toward phenotypic patterns of heart failure (HF) (Bolger et al, 2007;Pedrizzetti et al, 2010;Sengupta et al, 2012b). HF is associated with ventricular remodeling: modification of the LV, which progressively alters its function.…”

On the accuracy of intracardiac flow velocimetry methods

“…Particles used as the flow tracers are microbubbles filled with octafluoropropane encapsulated in either a lipid (DEFINITY Ò , Lantheus Medical Imaging, Inc.) or protein (Optison TM , GE Healthcare) outer shell [3,26], which are both FDA-approved for clinical use. This technique allows the velocity directions and streamlines, principal blood flow patterns, recirculation regions, and vortices to be drawn with reasonable confidence in a reproducible scheme [18,21,22,[27][28][29][30][31][32].…”