Mitral stenosis full

• Normal valve orifice area

  4–6 cm2
• Severe mitral stenosis


  Valve orifice area reduced to <1 cm2
• Consequences of severe mitral stenosis

  1. Left atrial pressure increases

  2. Left atrial hypertrophy and dilatation occur

  3. Pulmonary venous, pulmonary arterial and right heart pressures increase

  4. Pulmonary capillary pressure increases

  5. Pulmonary oedema develops, especially with atrial fibrillation and tachycardia

  6. Alveolar and capillary thickening and pulmonary arterial vasoconstriction (reactive pulmonary hypertension) partially prevent pulmonary oedema

  7. Pulmonary hypertension leads to right ventricular hypertrophy, dilatation and failure

  8. Tricuspid regurgitation occurs
• In order that sufficient cardiac output will be maintained, the left atrial pressure increases and left atrial hypertrophy and dilatation occur
• Consequently, pulmonary venous, pulmonary arterial and right heart pressures also increase
• The increase in pulmonary capillary pressure is followed by the development of pulmonary oedema particularly when the rhythm deteriorates to atrial fibrillation with tachycardia and loss of coordinated atrial contraction
• This is partially prevented by alveolar and capillary thickening and pulmonary arterial vasoconstriction (reactive pulmonary hypertension)
• Pulmonary hypertension leads to right ventricular hypertrophy, dilatation and failure with subsequent tricuspid regurgitation
• Mitral stenosis symptoms


  Usually no symptoms until valve orifice is moderately stenosed (area of 2 cm2)
• In Europe, severe calcific mitral stenosis does not usually occur until several decades after the first attack of rheumatic fever
• In the Middle or Far East, children of 10-20 years of age may have severe calcific mitral stenosis
• Symptoms of mitral stenosis

  1. Pulmonary venous hypertension and recurrent bronchitis leading to progressively severe dyspnoea

  2. Cough productive of blood-tinged, frothy sputum or frank haemoptysis

  3. Pulmonary hypertension leading to right heart failure and symptoms of weakness, fatigue and abdominal or lower limb swelling
• Atrial fibrillation in mitral stenosis

  Caused by the large left atrium, giving rise to symptoms such as palpitations
• Atrial fibrillation in mitral stenosis

  May result in systemic emboli, most commonly to the cerebral vessels resulting in neurological sequelae, but also to the mesenteric, renal and peripheral vessels
• Mitral stenosis


  • Associated with mitral facies or malar flush
  • Bilateral, cyanotic or dusky pink discoloration over the upper cheeks
  • Due to arteriovenous anastomoses and vascular stasis
• Mitral stenosis


  • Associated with small-volume pulse
  • Regular early on when most patients are in sinus rhythm
  • Irregular pulse as disease progresses and patients develop atrial fibrillation
  • Development of atrial fibrillation causes dramatic clinical deterioration
• Jugular veins


  If right heart failure develops, there is obvious distension of the jugular veins
• Jugular veins


  If pulmonary hypertension or tricuspid stenosis is present, the 'a'-wave will be prominent provided that atrial fibrillation has not supervened
• Palpation


  • There is a tapping impulse felt parasternally on the left side
  • This is the result of a palpable first heart sound combined with left ventricular backward displacement produced by an enlarging right ventricle
  • A sustained parasternal impulse due to right ventricular hypertrophy may also be felt
• Auscultation


  • Auscultation reveals a loud first heart sound if the mitral valve is pliable, but it will not occur in calcific mitral stenosis
  • As the valve suddenly opens with the force of the increased left atrial pressure, an 'opening snap' will be heard
  • This is followed by a low-pitched 'rumbling' mid-diastolic murmur best heard with the bell of the stethoscope held lightly at the apex with the patient lying on the left side
  • If the patient is in sinus rhythm, the murmur becomes louder at the end of diastole as a result of atrial contraction (pre-systolic accentuation)
• Severity of mitral stenosis

  • Presence of pulmonary hypertension
  • Closeness of opening snap to second heart sound
  • Length of mid-diastolic murmur
  • Immobility of valve cusps
• Presence of pulmonary hypertension


  Implies mitral stenosis is severe
• Recognizing pulmonary hypertension


  1. Right ventricular heave

  2. Loud pulmonary component of second heart sound

  3. Signs of right-sided heart failure (oedema, hepatomegaly)
• Pulmonary hypertension


  Results in pulmonary valvular regurgitation that causes an early diastolic murmur (Graham Steell murmur)
• Closeness of opening snap to second heart sound

  Proportional to severity of mitral stenosis
• Length of mid-diastolic murmur


  Proportional to severity of mitral stenosis
• Immobility of valve cusps


  Softens loud first heart sound and opening snap disappears
• Occurrence of pulmonary hypertension

  Increases intensity of pulmonary component of second sound and may quiet mitral diastolic murmur due to reduction in cardiac output
• Investigations

  Chest X-ray

  The chest X-ray usually shows a generally small heart with

  an enlarged left atrium Pulmonary venous hypertension is usually also present. Late in the course of the

  disease a calcified mitral valve may be seen on a penetrated or lateral view. The signs of pulmonary oedema or pulmonary

  hypertension may also be apparent when the disease is

  severe.
• Chest X-ray


  • Usually shows a generally small heart with an enlarged left atrium (Fig. 14.14)
  • Pulmonary venous hypertension is usually also present
  • Late in the course of the disease a calcified mitral valve may be seen on a penetrated or lateral view
  • Signs of pulmonary oedema or pulmonary hypertension may also be apparent when the disease is severe
• Electrocardiogram (ECG)


  • In sinus rhythm shows a bifid P wave owing to delayed left atrial activation (Fig. 14.72)
  • Atrial fibrillation is frequently present
  • As the disease progresses, the ECG features of right ventricular hypertrophy (right axis deviation and perhaps tall R waves in lead V1) may develop
• Echocardiogram


  A type of imaging technique
• Transthoracic echocardiography


  • Used to determine left and right atrial and ventricular size and function
• Mitral stenosis


  A condition where the mitral valve is narrowed
• Determining severity of mitral stenosis

  1. Planimetry of the mitral valve area on 2-dimensional echocardiography

  2. Measure pressure half time and mean pressure drop across the valve using continuous wave (CW) Doppler
• Wilkins score


  Used to determine if the valve is suitable for percutaneous valvotomy
• Estimating pulmonary artery pressure


  Measure degree of tricuspid regurgitation using continuous wave (CW) Doppler
• Mild mitral stenosis


  May need no treatment other than prompt therapy of attacks of bronchitis
• Infective endocarditis in pure mitral stenosis is uncommon
• Early symptoms of mitral stenosis


  Mild dyspnoea can usually be treated with low doses of diuretics