Hemodynamic Evaluation for Mitral Valve Replacement

Mitral valve replacement (MVR) alters the physiological hemodynamic environment in the left ventricle, potentially leading to complications. This in vitro study aims to investigate the impact of different mitral valves (native, bioprosthetic, and mechanical valves) on the flow and blood transport in the left ventricle.

A custom-made left heart simulator was used, considering three different mitral valves: native, bioprosthetic, and mechanical valves. Time-resolved tomographic particle image velocimetry (Tomo-PIV) was employed to obtain three-dimensional ventricular flow. The particle residence time and the apical-transit ratio were quantified by tracking virtual tracers within the measured flow fields.

Prosthetic valves fundamentally change diastolic vortex structures. The native valve forms a saddle-shaped vortex ring, the bioprosthetic valve produces a nearly circular vortex ring, and the mechanical valve generates a crescent-shaped starting vortex below the leaflets. Quantitatively, the native valve results in the shortest blood residence time and the highest apical-transit ratio, indicating optimal blood transport efficiency compared to both bioprosthetic and mechanical valves.

Efficient left ventricular pumping requires not only timely ejection but also physiological vortex-driven apical washout. This insight represents a key consideration for future prosthetic valve design.