<unk>  stenosis (MS) is most commonly secondary to acute rheumatic fever. Generally, the initial valvulits is associated with valvular regurgitation but over a period of 2 or more years, the commissures fuse and the valves thicken and calcify. The chordal supporting structure also calcifies and retracts. The result is the typical “fish mouth deformity”. 70% of the time; the<unk>  valve is involved in isolation, and 25% of the time; the aortic valve is involved as well. The tricuspid and pulmonic valves are involved less commonly.
The normal<unk>  valve orifice area is 4-6 cm2.<unk>  stenosis occurs when the orifice area is reduced to at least 2.2 cm2. This result in a gradient across the<unk>  valve which is the haemodynamic hallmark of the disease.
Mitral stenosis anatomy and pathophysiology
Tricuspid stenosis epidemiology and demographics
Mitral stenosis epidemiology and demographics
Bicuspid aortic stenosis epidemiology and demographics
Aortic stenosis epidemiology and demographics
Diastolic dysfunction epidemiology and demographics
Aortic regurgitation pathophysiology
Tricuspid regurgitation pathophysiology