Mitral Stenosis

Question 1

Mitral stenosis presentation

Answer 1

This patient has been complaining of reduced exercise tolerance. Examine his heart and elucidate the cause of his symptoms.

Question 2

Clinical signs of Mitral stenosis

Answer 2

1. Malar flush
2. Irregular pulse if AF is present
3. Tapping apex (palpable first heart sound)
4. Left parasternal heave if pulmonary hypertension is present or enlarged left atrium
5. Auscultation
   - Loud first heart sound.
   - Opening snap (OS) of mobile mitral leaflets opening followed by a mid-diastolic murmur (MDM), which is best heard at the apex, in the left lateral position in expiration with the bell.
   - Presystolic accentuation of the MDM occurs if the patient is in sinus rhythm.
   - If the mitral stenosis is severe then the OS occurs nearer A2 and the MDM is longer.
   6. Haemodynamic significance
   - Pulmonary hypertension: functional tricuspid regurgitation, right ventricular heave, loud P2.
   - LVF: pulmonary oedema, RVF: sacral and pedal oedema.
   7. Endocarditis
   8. Embolic complications: stroke risk is high if mitral stenosis + AF

Question 3

Auscultation in Mitral Stenosis

Answer 3

1- Loud first heart sound.
2- Opening snap (OS) of mobile mitral leaflets opening followed by a mid-diastolic murmur (MDM), which is best heard at the apex, in the left lateral position in expiration with the bell.
3- Presystolic accentuation of the MDM occurs if the patient is in sinus rhythm.
4- If the mitral stenosis is severe then the OS occurs nearer A2 and the MDM is longer.

Question 4

Causes of Mitral stenosis

Answer 4

Congenital: (rare)
Acquired
1. Rheumatic (commonest)
2. Senile degeneration
3. Large mitral leaflet vegetation from endocarditis (mitral ‘plop’ and late diastolic murmur)

Question 5

Differential diagnosis of Mitral stenosis

Answer 5

1. Left atrial myxoma
2. Austin–Flint murmur

Question 6

Investigation of Mitral stenosis

Answer 6

1. ECG: p‐mitrale (broad, bifid) and atrial fibrillation
2. CXR: enlarged left atrium (splayed of carina), calcified valve, pulmonary oedema
3. TTE/TOE:
- – Valve area (<1.0 cm2 is severe),
- – Cusp mobility, Calcification
- – Left atrial thrombus,
- – Right ventricular failure

Question 7

Management of Mitral stenosis

Answer 7

1. Medical: + AF: rate control and oral anticoagulants, diuretics
2. Mitral valvuloplasty: if pliable, non‐calcified with minimal regurgitation and no left atrial thrombus
3. Surgery:
- Closed mitral valvotomy (without opening the heart) or
- Open valvotomy (requiring cardiopulmonary bypass) or
- Valve replacement

Question 8

Prognosis of Mitral stenosis

Answer 8

• Latent asymptomatic phase 15–20 years;
• NYHA > II – 50% mortality at 5 years.

Question 9

Pathophysiology of Rheumatic fever

Answer 9

• Immunological cross‐reactivity between Group A β haemolytic streptococcal infection, e.g. Streptococcus pyogenes and valve tissue

Question 10

Duckett–Jones diagnostic criteria of Rheumatic fever

Answer 10

Proven β haemolytic streptococcal infection diagnosed by throat swab, rapid antigen detection test (RADT), anti streptolysin O titre (ASOT) or clinical scarlet fever
Plus 2 major or 1 major and 2 minor:
Major: Carditis, Polyarthritis, Chorea, Erythema marginatum, Subcutaneous nodules.
Minor: Raised ESR, Raised WCC, Arthralgia, Previous RhF, Pyrexia, Prolonged PR interval

Question 11

Treatment of Rheumatic fever

Answer 11

Rest, high‐dose aspirin and penicillin

Question 12

Prophylaxis of Rheumatic fever

Answer 12

• Primary prevention: penicillin V (or clindamycin) for 10 days
• Secondary prevention: penicillin V for about 5–10 years