Echocardiography is the key diagnostic tool used for determination of rheumatic valvular disease. Carpentier's type IIIa is the most common dysfunction seen in patients with rheumatic mitral valve. The characteristic lesions are commissural fusion with or without calcification, leaflet thickening / retraction, and chordae fusion and shortening. The hemodynamic consequence of this valvular dysfunction is mitral regurgitation associated with varying degrees of mitral stenosis.
Type IIIa dysfunction of the posterior leaflet associated with limited prolapse of the anterior leaflet (mostly A2 segment) is very characteristic of rheumatic mitral valve disease.
The presence of associated valvular lesions involving the aortic and tricuspid valves is strongly in favor of rheumatic etiology of valvular heart disease.
Echocardiography is also critical in assessing the mobility of the anterior leaflet, the extent of subvalvular apparatus lesions, and the presence and the extent of valvular calcification as they all predict the feasibility of valve reconstruction.
Finally, echocardiography is used to obtain quantitative measures such as mitral valve orifice area applying the continuity equation. Transvalvular peak and mean gradients are calculated with continuous-wave and pulsed-Doppler echocardiography using the modified Bernoulli equation. In patients with mitral stenosis and minimal symptoms, it is important to calculate transvalvular gradient at rest and during exercise. The table shown below indicates the grading of mitral stenosis.
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