Transmitral gradients with varying mitral valve area, heart rate, and cardiac output

Using the Gorlin formula, the relationship between heart rate, mean transmitral gradient, and four different MVAs (2, 1.5, 1, and 0.7 cm²) are shown at a cardiac output of 5 liters/min. For each decrement in MVA, there is a steeper rise in mean transmitral gradient with increasing heart rates (shorter diastolic filling times).
In a patient with an MVA of 1.5 cm², the impact of an increase in cardiac output (9 liters/min) at heart rate of 100 beats/min is shown in the arrowed black box; this scenario is often encountered during exertion and in pregnant women. The mean transmitral gradient is similar to that seen in a patient with severe mitral stenosis (MVA of 0.7 cm²) at heart rate of 88 beats/min.