Reduced Exercise Tolerance

Case Vignette

A 35-year-old woman presents with exertional dyspnoea and reduced exercise tolerance. Please examine her cardiovascular system.

Positive Findings

1. General:

  • Malar Flush: Pink-purple discolouration over the cheeks sparing the nasal bridge.

2. Pulse:

  • Irregularly Irregular: Suggestive of atrial fibrillation.

3. Chest Examination:

  • Palpation:
    • Tapping apex beat (suggests a loud first heart sound and pliable valve).
    • Left parasternal heave: Indicates right ventricular hypertrophy from pulmonary hypertension.
  • Auscultation:
    • Loud S1.
    • Opening Snap: High-pitched sound following S2.
    • Mid-diastolic Rumbling Murmur: Low-pitched, heard at the apex, best in the left lateral decubitus position during expiration.
    • Presystolic Accentuation: Louder murmur just before S1 in sinus rhythm (absent in AF).

4. Signs of Pulmonary Hypertension (if severe):

  • Raised JVP.
  • Loud or palpable P2.
  • Right ventricular heave.

Relevant Negative Findings

  • No signs of systemic embolisation (e.g. stroke or limb ischaemia).
  • No signs of infective endocarditis.
  • No evidence of pulmonary oedema (e.g. basal crepitations or respiratory distress).
  • No peripheral oedema or ascites indicating right-sided heart failure.

What is the most likely diagnosis?

The findings are consistent with Mitral Stenosis, most likely due to rheumatic fever, complicated by atrial fibrillation and pulmonary hypertension.

What is your differential diagnosis?

  1. Other causes of mitral stenosis:
  • Connective tissue disease (SLE or rheumatoid arthritis)
  • Carcinoid heart disease
  • Drugs e.g. cabergoline, methysergide
  • Mucopolycaccharidoses
  • Parachute Mitral Valve: Congenital abnormality leading to stenosis.
  • Severe Mitral Annular Calcification: Common in elderly patients.
  1. Other Structural Cardiac Lesions:
  • Left Atrial Myxoma: Presents with systemic symptoms and positional murmur.
  • Pulmonary Vein Stenosis
  • Cortriatriatum: a congenital abnormality in which the left (or right) atrium is divided by a membrane, creating a triatrial heart and separating the pulmonary veins from the mitral valve.
  1. Other Mid-Diastolic Murmurs:
  • Tricuspid Stenosis: Louder in inspiration, murmur at the left lower sternal edge.
  • Austin Flint Murmur: Severe aortic regurgitation causing functional mitral stenosis.

How would you investigate this patient?

  1. Primary Diagnostic Tests:
  • Echocardiography (TTE/TOE):
  • Mitral Valve Area (MVA):

• Mild: 1.5–2.2 cm².

• Moderate: 1.0–1.5 cm².

• Severe: <1.0 cm².

  • Mean Gradient: Indicates severity.

• Left atrial size and thrombus.

• Pulmonary artery pressure.

• Wilkins score for suitability for balloon valvuloplasty.

  • ECG:

• P mitrale (broad, bifid P waves).

• Atrial fibrillation.

• Right ventricular hypertrophy in severe cases.

  • Chest X-ray:

• Left atrial enlargement (splayed carina, double right heart border).

• Pulmonary congestion or oedema.

  1. Additional Investigations:
  • Cardiac Catheterisation: If echo findings are inconclusive or to assess pulmonary pressures and coronary artery disease.

How would you manage this patient?

Medical:

  1. Symptomatic Relief:
  • Diuretics or long-acting nitrates: Reduce pulmonary venous congestion.
  • Beta-Blockers or Calcium Channel Blockers: Slow heart rate in AF to improve diastolic filling.

2. Anticoagulation:

  • Indicated for all patients with atrial fibrillation or left atrial thrombus (use warfarin as NOACs are not licensed for MS).
  • Consider if there is significant atrial enlargement, even if in sinus rhythm.

3. Infective Endocarditis Prophylaxis:

  • Not routinely recommended, but good dental hygiene is essential.

Interventional:

1. Percutaneous Balloon Mitral Valvuloplasty (PBMV):

Indications:

  • Symptomatic severe MS.
  • Asymptomatic severe MS with pulmonary hypertension or new-onset AF.

Suitable if:

  • Wilkins score ≤8.
  • No significant mitral regurgitation or left atrial thrombus.

2. Surgery:

  • Mitral Valve Replacement (MVR): For patients unsuitable for PBMV due to calcified valves, severe mitral regurgitation, or left atrial thrombus.
  • Open Valvotomy: Less commonly performed but may be an option.

Follow-Up:

  • Annual review for asymptomatic patients with mild to moderate MS.
  • Monitor for changes in symptoms, rhythm (AF), or pulmonary pressures.

Viva Questions

1. What are the complications of Mitral Stenosis?

  • Pulmonary hypertension, right-sided heart failure, atrial fibrillation, systemic embolism, haemoptysis (due to rupture of pulmonary–bronchial venous connections in pulmonary venous hypertension), hoarse voice (Ortner's syndrome; left atrial dilatation compressing the recurrent laryngeal nerve) and infective endocarditis.

2. How do you assess the severity of MS clinically?

  • Interval between S2 and opening snap (shorter = more severe).
  • Duration of diastolic murmur (longer = more severe).
  • Signs of pulmonary hypertension (loud P2, RV heave).
  • Presence of AF.

3. What are the contraindications for PBMV?

  • Moderate or severe mitral regurgitation.
  • Left atrial thrombus despite anticoagulation.

4. What is the prognosis for untreated severe MS?

  • Median survival of 2–3 years after onset of NYHA III/IV symptoms without intervention.