Abstract

Percutaneous mitral valve edge-to-edge repair is a viable solution in high-risk patients with severe symptomatic mitral regurgitation. However, the generated double-orifice configuration poses challenges for the evaluation of the hemodynamic performance of the mitral valve and may alter flow patterns in the left ventricle during diastole. The purpose of the present in vitro study is to provide new insight into the spatial-temporal hemodynamics of the flow distal to simulated percutaneous edge-to-edge repair by employing a high resolution, flow diagnostic method, Phase Locked and Time Resolved Digital Particle Image Velocimetry inside the LV.

A custom-made mitral valve was developed and two configurations were tested: a single orifice valve with mitral regurgitation and a double-orifice mitral valve configuration. The hemodynamic performance of the valve was evaluated using Doppler echocardiography and catheterization. The flow patterns in the left ventricle were investigated using Particle Image Velocimetry.

Edge-to-edge repair significantly reduced the regurgitant volume. There was a good agreement between Doppler and catheter transmitral pressure gradients. There was a good match between maximal velocity measured by Doppler and particle image velocimetry. Vortex development in the left ventricle during diastole was significantly different after repair.

There was a good agreement between Doppler and catheter measurements of transmitral pressure gradient following simulated edge-to-edge repair. Flow in the left ventricle was significantly altered by the repair and led to higher energy dissipation during diastole.