All Those AS Gradients

Aortic stenosis (AS) is frequently encountered in echocardiography laboratories. Accurate evaluation of AS severity is essential for proper decisions regarding optimal treatment and timing of interventions. The severity of aortic stenosis is determined by the aortic valve area (at normal flow state), however, multiple criteria are utilized to grade AS severity: calculated aortic valve area, velocity/gradients across the valve, valvuloarterial impedance, valve calcifications, etc. The importance of accurately assessing AS severity and defining the subtype of AS cannot be overstated. It is essential to use meticulous techniques, including imaging from all views and utilizing the non-imaging transduced in order to measure maximal trans-aortic velocities. When discussing trans-aortic gradients it is necessary to specify exactly which gradient is reported—both for understanding the hemodynamic significance of the finding, as well as accurate communication when different techniques are utilized.