Pathophysiology
After a latency period usually between 10 to 20 years after rheumatic fever, symptoms may occur indicating that the Mitral Valve is thickening and calcifications/clots are formed on the valve itself, narrowing the opening. Normally the mitral opening is between 4 to 6 sq. cm. in adults. As the opening is getting smaller left atrial pressure is increased to maintain normal flow. The increase in left atrial pressure will lead to raised pulmonary venous and capillary pressure with dyspnea as result. Chronic elevated pressure will further promote pulmonary hypertension, tricuspid and pulmonary incompetence and eventually right heart failure.

Other complications related to Mitral Stenosis are:

1: Formation of clots on the left atrial walls that may cause embolism, (Mural Thrombi)

2: Atrial Fibrillation: Elevated atrial pressure will dilate and is likely to fibrillate, which further compromises the filling of the left ventricle.