Impact of mitral valve interventions on left ventricular hemodynamics: Insights into energy loss and flow dynamics

Objectives

Left ventricular vortex dynamics play a crucial role in cardiac function but are significantly altered by mitral valve diseases or surgical interventions. Such hemodynamic changes may lead to maladaptive intracardiac vortices, potentially triggering pathways associated with progressive left ventricular remodeling and thrombosis. This study assessed left ventricular hemodynamics under both physiological and pathological conditions using a biohybrid in vitro platform, aiming to analyze the impact of these conditions on cardiac function.

Methods

An in vitro platform was established to simulate 6 mitral valve conditions: healthy, mitral regurgitation, bioprosthetic valve replacement, mechanical valve replacement (in 2 orientations), and transcatheter mitral valve edge-to-edge repair. Flow fields within the left ventricle were captured using 4-dimensional particle image velocimetry, including mean flow fields, vortex depth, vortex transversal position, viscous shear stress, and energy dissipation.

Results

Mitral regurgitation preserved vortex structure compared with healthy conditions. Mechanical valves altered vortex direction and reduced vortex transversal position (0.66-0.47, P < .001), potentially impairing pump efficiency and increasing cardiac workload. Bioprosthetic valves displaced the vortex away from the apex, decreasing vortex depth (0.64-0.32, P < .001), which may elevate apical thrombosis risk. Transcatheter mitral valve edge-to-edge repair reduced mitral regurgitation but significantly increased energy dissipation and viscous shear stress, indicating higher cardiac energy expenditure and disturbed flow.

Conclusions

Preserving native valve function optimizes left ventricular hemodynamics, whereas valve replacements and transcatheter mitral valve edge-to-edge repair alter flow patterns, increasing cardiac workload and thrombotic risks. These findings underscore the importance of assessing left ventricular flow dynamics in the treatment of mitral regurgitation.