Hemodynamic principles of prosthetic aortic valve evaluation in the transcatheter aortic valve replacement era

Evaluating the hemodynamic performance of aortic valve prostheses has relied primarily on echocardiography. This involves calculating the trans-prosthetic valve mean gradient (MG) and aortic valve area (AVA), and assessing for valvular and paravalvular regurgitation in a fashion similar to the native aortic valve. In conjunction with other echocardiographic and nonechocardiographic parameters, MG and AVA are used to distinguish between prosthesis stenosis, prosthesis patient mismatch, pressure recovery, increased flow, and measurement errors. This review will discuss the principles and limitations of echocardiographic evaluation of aortic valve prosthesis following surgical, and transcatheter aortic valve replacement and in comparison to invasive hemodynamics through illustrative clinical cases.