Mitral stenosis

• Mitral stenosis:

  • Narrowing of the mitral valve, which results in decreased filling of the left ventricle during systole, and increased left atrial pressure
  • Associated with a rumbling mid-diastolic murmur heard loudest over the apex
• Rheumatic heart disease is the most common cause of mitral stenosis:

  • Complication of infection by group A streptococcus pharyngitis
  • Occurs due to molecular mimicry - atrial and mitral valves are most commonly affected
• Rare causes of MS:

  • Congenital
  • Calcification
  • Radiation
  • Carcinoid associated valve disease
• Symptoms:

  • Normally presents with exertional dyspnoea
  • Haemoptysis - vascular congestion causing rupture of thin walled bronchial veins
  • Chest pain
• Signs:

  • Mid-diastolic murmur with an opening click
  • Murmur heard loudest over the apex and in the left lateral position on expiration
  • Irregularly irregular pulse - atrial fibrillation is common
  • Malar flush - chronic CO2 retention and its vasodilatory effects
  • Signs of pulmonary hypertension - right ventricular heave
  • Signs of right heart failure - raised JVP, peripheral oedema, hepatomegaly
• Patients may occasionally present with Ortner syndrome - a horse voice that occurs secondary to left atrial enlargement causing a left recurrent laryngeal nerve palsy.
• Thromboembolism:

  • Patients with mitral stenosis are at greatly increased risk of thromboembolic events
  • Clots that develop in a dilated left atrium, often in the presence of atrial fibrillation, may throw off emboli into the systemic circulation
  • Patients may present with a stroke