Mitral stenosis is always due to rheumatic fever. After the initial episode of rheumatic fever, symptoms of mitral stenosis may not appear for 10 years or more. Scarring of the mitral valve due to rheumatic fever causes turbulent flow of blood which in turn causes more scarring and contraction over many years. Usually severe mitral stenosis takes about 20 to 30 years to develop after the last known bout of rheumatic fever.

There is pulmonary oedema and dyspnoea. In the beginning dyspnoea appears with extreme exertion, but with more severe stenosis it occurs with lesser degrees of exertion. Chronic cough which becomes worse at night in recumbent position. Orthopnea and paroxysmal nocturnal dyspnoea, haemoptysis are there. Due to right heart failure, there will be venous distension, peripheral oedema and hepatic enlargement. Arterial embolism, angina pectoris are also found.

The patients are usually thin and frail with muscular wasting, typical of suffering from chronic illness. Dilated neck veins are often visible. Rales are frequently audible over the lung bases. There is increased first heart sound, an opening snap and a diastolic murmur at the apex. A short apical systolic murmur may be heard in patients with pure mitral stenosis without any associated mitral insufficiency.

Investigations-

1.   Echocardiography.

2.   Lateral chest radiography.

3.   E.C.G.

4.   Cardiac catheterization.

Treatment-

Mitral stenosis as such is first treated by medical means. If this fails, operation is considered.