Inverted Aortic Prosthesis in the Mitral Position: Is Upside Down Always the Right Side Up?

Evaluation of prosthetic valve function is a challenging task. The clinician has to employ multiple parameters to quantify dysfunction (if present), the results of which can be mutually discrepant. This results from heterogeneity in the design of the valves themselves, implantation techniques, and both intra- and interpatient hemodynamic variability. Specifically, the location and angle of valve implantation can have a profound impact on its flow characteristics that can lead to symptoms despite satisfactory mechanical function. The authors present the case of inverted implantation of a prosthesis designed for the aortic position in the mitral annulus and resultant mitral stenosis. What follows is an examination of how the flow characteristics, such as pressure recovery, energy loss, and vortex formation, create a gradient that could not be explained by valve size alone.