An underestimated valve area could lead to a diagnosis of severe aortic stenosis when not appropriate. Recently, there has been an increase in literature published on the diagnosis of severe aortic stenosis with a low mean gradient and preserved left ventricular function as measured by ejection fraction (EF). It is possible that many of these patients do not have severe AS but are misclassified as such because underestimation of the LVOT diameter leads to underestimation of aortic valve area as calculated by the continuity equation. This study aims to define the true incidence of these patients by ensuring the aortic valve area is measured as accurately as possible based on current imaging procedures.