Causes of mitral stenosis

  • Rheumatic heart disease (rare in the UK, but still common in the developing world and in aboriginal populations)
  • Congenital
  • Left atrial myxoma
  • Connective tissue disease (predominantly female)

Diagnostic criteria for rheumatic heart disease, remains the Jones criteria with Major and Minor criteria. Major:

  • Carditis
  • Polyarthritis (migratory)
  • Erythema marginatum
  • Chorea
  • Subcutaneous nodules

Minor:

  • Fever
  • Arthralgia
  • Raised inflammatory markers
  • Prolonged P=R interval on ECG

ECG changes:

  • Atrial fibrillation/flutter
  • P-pulmonale
  • Right axis deviation
  • Right ventricular hypertrophy, if in pulmonary hypertension

Diagnosis is confirmed on echocardiogram (including the mitral valve area):

  • 1.5-2.2 cm2 = mild stenosis
  • 1.0-1.5 cm2 = moderate stenosis
  • Less than 1 cm2 = severe stenosis

Complications of mitral stenosis

The right ventricle is the driving force of blood through the mitral valve. As such, with a stenotic mitral valve, the increased pressure required leads to reassure overload of the right ventricle, and hence right ventricular failure if left untreated, with associated pulmonary hypertension.

Cardiac arrhythmias associated with mitral stenosis:

  • Atrial fibrillation/flutter
  • Paroxysmal atrial fibrillation
  • Premature atrial ectopics

Management

Medical management includes anti-coagulation and rate control for atrial fibrillation/flutter. Also, anti-microbial prophylaxis during certain surgical procedures.

Moderate to severe stenosis should be considered for intervention. Balloon mitral valvuloplasty (which can delay the need for a valve replacement for years, but has low rates of actual cure) or mitral valve replacement are still the mainstays of treatment.