Mitral stenosis (MS)

Aetiology:

• Rheumatic fever (almost all cases are due to this)
• Lutembacher’s syndrome (combination of acquired MS and an ADS)
• Calcification and fibrosis of the valve, valve ring and chordae tendineae (elderly)
• Congenital mitral stenosis (rare)

Complications of MS:

• Atrial fibrillation
• Systemic embolization
• Pulmonary HT
• Pulmonary infarction
• Chest infections
• Tricuspid regurgitation
• Right ventricular failure
• IE (rare)

Symptoms:

• Asymptomatic until valve orifice is reduced from 5cm² to 2cm²
• Progressively severe dyspnoea (due to pulmonary HT and recurrent bronchitis)
• A cough productive of blood-tinged, frothy sputum is quite common
• Frank haemoptysis may occur
• Symptoms of right-heart failure (fatigue, weakness, abdominal/lower limb swelling)
• Palpitations (due to AF)
• AF may result in systemic embolization, commonly to the cerebral vessels

Signs:

Pulse: AF (irregularly irregular)

RV: Heaving

Apex: Tapping, non-displaced

Sound: Loud S1, loud P2, opening snap

Murmur: Mid-diastolic rumble at apex, best heard with pt on left-side

Investigations:

CXR:

• Small heart
• Enlarged left atrium
• Signs of pulmonary oedema may be apparent when the disease is severe

ECG:

• In sinus rhythm, the ECG shows a bifid P wave (P mitrale) due to delayed left atrial activation
• AF is frequently present
• As the disease progresses, there features of right ventricular hypertrophy may develop:
• Right axis deviation

Echocardiography

Treatment:

• Mild MS may need no treatment other than prompt therapy of attacks of bronchitis
• Antibiotic therapy is advised to prevent IE (although rare)
• Early symptoms of MS (e.g. mild dyspnoea) can be treated with diuretics
• The onset of AF requires treatment with digoxin and anticoagulation
• If pulmonary HT develops, surgical relief of the MS is advised

There are 4 operative measures:

• Trans-septal balloon valvotomy
• Closed valvotomy
• Open valvotomy
• Mitral valve replacement