Marked discrepancy in pressure gradient between Doppler and catheter examinations on Medtronic Mosaic valve in aortic position

A 71-year-old woman underwent aortic valve replacement with 23 mm Medtronic Mosaic Ultra valve 4 years ago because of aortic stenosis. Although she had been asymptomatic since the operation, echocardiography showed 4 m/s of transprosthetic valve flow that implied early prosthetic valve failure. Catheter examination revealed that the mean transvalvular pressure gradient during systole was 15.1 mmHg on simultaneous pressure recording, and calculated valve area 1.82 cm². Her body surface area was 1.56 m². Prosthetic valve failure and prosthesis-patient mismatch were both denied. The discrepancy between Doppler study data and catheter data seemed to be due to fluid dynamical pressure recovery phenomenon. Net pressure difference between the left ventricle and the aorta may be significantly smaller than that estimated using Bernoulli's equation from transvalvular flow speed in some patients after aortic valve replacement.