Fluid mechanics of a model mitral valve and left ventricle

aortic valve. The bicuspid mitral valve was seen to achieve most of its closure during diastole. This was shown to be due to a ring-vortex occupying the left ventricle together with flow deceleration through the mitral ring during the latter part of diastole. The vortex was asymmetrical in the model, because of the shape of the ventricle, and this caused the anterior cusp to close earlier in diastole than the posterior cusp. Enlargement of the ventricle eliminated the vortex and resulted in later closure of the mitral valve. The effect of atrial systole on valve closure was studied experimentally and theoretically. The closure mechanism of the mitral valve has been studied by many investigators with widely differing techniques and results. Henderson and Johnson (1912) suggested that the mitral valve was closed by fluid mechanic forces, and argued that the inertia of blood flowing through the mitral ring produced in its wake a negative pressure, and called this effect the ‘breaking o