Background: Pressure recovery is not taken into account when calculating trans-prosthetic gradients after mechanical valve replacement using Doppler echocardiography. This may lead to underestimation of valvular performance.
Methods: Simultaneous measurement of Doppler and direct trans-prosthetic gradients was performed in a circulatory mock loop simulator with physiologic parameters at different heart rates and cardiac outputs for small-sized aortic Omnicarbon tilting disc valves (19 - 21 mm).
Results: In all adjustments the Doppler gradient significantly overestimated the net transvalvular gradient. The amount of pressure recovery averaged 59.3 %.
Conclusions: Doppler echocardiography does not allow for pressure recovery, which is a significant phenomenon in the hemodynamic function of the Omnicarbon tilting disc valve. Valve performance is much better than expected from Doppler gradients.