Valve Orifice Area Alone is an Insufficient Index of Aortic Stenosis Severity: Effects of the Proximal and Distal Geometry on Transaortic Energy Loss Russell S. Heinrich PhD, Richard H. Marcus MD, Ann E. Ensley BS, David E. Gibson BS, Ajit P. Yoganathan PhD As predicted by fundamental fluid mechanical theory, simulated left ventricular work and energy loss in aortic stenosis are influenced not only by the effective stenotic valve orifice area, but also by the geometry of the inflow and outflow conduits, proximal and distal to the valve. These findings might explain clinically observed discrepancies between valve orifice area and the onset of the classical symptoms of severe aortic stenosis that reflect the left ventricular workload. Consideration of the left ventricular work in addition to the effective valve orifice area might enhance clinical evaluation, prognostication and risk stratification among patients with severe aortic stenosis.

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