[2] Signs and symptoms of mitral stenosis include the following: Fatigue and weakness increase with exercise and pregnancy.

Once symptoms of mitral stenosis begin to develop, progression to severe disability takes 9.2 ± 4.3 years.

In individuals with severe mitral stenosis, the left ventricular filling is dependent on the atrial kick.

[10] Mitral stenosis typically progresses slowly (over decades) from the initial signs of mitral stenosis to NYHA functional class II symptoms to the development of atrial fibrillation to the development of NYHA functional class III or IV symptoms.

Once an individual develops NYHA class III or IV symptoms, the progression of the disease accelerates and the patient's condition deteriorates.

[3] If pulmonary hypertension secondary to mitral stenosis is severe, the P2 (pulmonic) component of the second heart sound (S2) will become loud.

[citation needed] With severe pulmonary hypertension, a pansystolic murmur produced by functional tricuspid regurgitation may be audible along the left sternal border.

[13] In most cases, the diagnosis of mitral stenosis is most easily made by echocardiography, which shows left atrial enlargement, thick and calcified mitral valve with narrow and "fish-mouth"-shaped orifice and signs of right ventricular failure in advanced disease.

[3] It can also show decreased opening of the mitral valve leaflets, and increased blood flow velocity during diastole.

The trans-mitral gradient as measured by Doppler echocardiography is the gold standard in the evaluation of the severity of mitral stenosis.

[citation needed] Another method of measuring the severity of mitral stenosis is the simultaneous left and right heart chamber catheterization.

If a trans-septal puncture is made during right heart catheterization, however, the pressure gradient can accurately quantify the severity of mitral stenosis.

[citation needed] Chest X-ray may also assist in diagnosis, showing left atrial enlargement.

[15] The indication for invasive treatment with either a mitral valve replacement or valvuloplasty is NYHA functional class III or IV symptoms.

[16] To determine which patients would benefit from percutaneous balloon mitral valvuloplasty, a scoring system has been developed.

[17] Superb results with valvotomy are seen in individuals with a crisp opening snap, score < 8, and no calcium in the commissures.

Under local anaesthetic, a catheter with a special balloon is passed from the right femoral vein, up the inferior vena cava and into the right atrium.

Second, the proximal portion is dilated, in order to fix the centre segment at the valve orifice.

It can lead to pulmonary edema and hemodynamic compromise, necessitating urgent surgical mitral valve replacement.

[citation needed] Although the immediate results of PBMV are often quite gratifying, the procedure does not provide permanent relief from mitral stenosis.

Long-term follow-up data from patients undergoing PBMV indicates that up to 70–75% individuals can be free of restenosis 10 years following the procedure.