Q. What is Stenotic and regurgitant lesions?

The normal cardiac valves offer little resistance to blood flow even when flow velocity is high. When stenosis develops, the valve orifice offers greater resistance to flow resulting in a pressure drop (pressure gradient) across the valve. At any given stenotic orifice size, greater flow across the valve produces a greater pressure gradient across the valve. Based on this concept, the Gorlin formula was derived for calculation of cardiac valve orifices from flow and pressure gradient data.