Mitral stenosis

Background

Drawing of mitral stenosis.

Mitral valve stenosis from rheumatic heart disease on pathology (thickened mitral valve, thickened chordae tendineae, hypertrophied left ventricular myocardium).

• Most common cause (~85%) is rheumatic fever
• Chronic rheumatic disease uncommon in western world, but still very common in developing countries
  • USA - 0.25 per 1000 people
  • India and Pakistan - 5 per 1000 people
  • Cambodia - 21.5 per 1000 people
  • Mozambique - 30.4 per 1000 people
• Other etiologies:
  • Stenotic annular calcification (~12%)
    • Degenerative/age-related
    • Post-infectious
  • Congenital (~0.6%)
    • Annulus hypoplasia
    • Parachute
    • Double orifice

Clinical Features

Phonocardiograms of common cardiac murmurs.

• Mid-diastolic murmur
• Symptoms and complications
  • Exertional dyspnea
  • PND
  • Acute pulmonary edema
  • Tricuspid regurgitation
  • Cor pulmonale
  • Hemoptysis (pulmonary hypertension > ruptured bronchial vein)
  • Atrial fibrillation
  • Thromboembolism
  • Precipitants:
    • Anemia
    • Pregnancy
    • Infection
    • A-fib

Complications

• Systemic emboli
• CHF
• Atrial fibrillation
• Endocarditis

Differential Diagnosis

Valvular Emergencies

• Mitral stenosis
• Mitral regurgitation
  • Mitral valve prolapse
• Aortic stenosis
• Aortic regurgitation

Evaluation

Severity of mitral stenosis

Degree of mitral stenosis	Mean gradient	Mitral valve area
Progressive mitral stenosis	<5 mmHg	>1.5 cm2
Severe mitral stenosis	5–10 mmHg	1.0–1.5 cm2
Very severe mitral stenosis	> 10 mmHg	< 1.0 cm2

• ECG
  • RAD
  • Biphasic P waves
  • Most common arrhythmia is AF
• CXR
  • Straightening of right heart border
• Echocardiography

Management

• Diuretics
  • Alleviates pulmonary congestion
• A-fib treatment
• Hemoptysis
  • Consider transfusion / surgery consult
• Endocarditis prophylaxis after replacement

See Also

• Valvular Emergencies
• Heart Murmurs