Pressure Recovery in Bileaflet Heart Valve Prostheses

Abstract

Gradients across the St Jude valve measured by Doppler ultrasound are higher than transvalvular or net catheter gradients due to downstream pressure recovery. This is more marked for Doppler gradients based on centerline velocities than side orifice velocities and is more pronounced for valves in an aortic than a mitral configuration. Therefore, to be comparable with invasive transvalvular catheter gradients, either Doppler gradients should be calculated based on side orifice velocity measurements or the Doppler gradient calculation should include the pressure loss coefficient when based on central orifice velocities.