Figure 50-23 The gradient across mitral valves of various sizes is plotted according to mitral valve flow. Note that when mitral valve flow is in the normal range (150 to 200 mL/sec of diastole), the gradient across a mitral valve area (MVA) of 2 cm² is 4 to 6 mm Hg. With an MVA of 1 cm² , the gradient with normal mitral valve flow is 18 to 28 mm Hg. (Redrawn from Dalen JE, Alpert JS [eds]: Valvular Heart Disease, 2nd ed. Boston, Little, Brown, 1987.)