Mitral Stenosis

Question 1

What is the definition of mitral stenosis?

Answer 1

Mitral valve narrowing causing obstruction to blood flow from the left atrium to the left ventricle

Question 2

What is the epidemiology of mitral stenosis?

Answer 2

Incidence is declining because rheumatic fever is becoming more and more rare

Question 3

What is the aetiology of mitral stenosis?

Answer 3

MAIN CAUSE: Rheumatic Heart Disease (90% of cases)

Rare causes of mitral stenosis:

• Congenital mitral stenosis
• SLE
• Rheumatoid arthritis
• Endocarditis
• Atrial myxoma

Question 4

What are the presenting symptoms of mitral stenosis?

Answer 4

May be ASYMPTOMATIC

Fatigue

Shortness of breath on exertion

Orthopnoea

Palpitations (related to AF)

Rare symptoms:

• Cough
• Haemoptysis
• Hoarseness caused by compression of left recurrent laryngeal nerve by an enlarged left atrium

Question 5

What are the signs of mitral stenosis upon physical examination?

Answer 5

Peripheral cyanosis

Malar flush

Irregularly irregular pulse (if in AF)

Apex beat undisplaced and tapping

Parasternal heave (due to right ventricular hypertrophy secondary to pulmonary hypertension)

Loud S1 with opening snap

Mid-diastolic murmur

Evidence of pulmonary oedema on lung auscultation (if decompensated)

Question 6

What are the appropriate investigations for mitral stenosis?

Answer 6

ECG:
- May be normal
May see p mitrale (broad bifid p wave caused by left atrial hypertrophy)
- May see AF
- Evidence of right ventricular hypertrophy may be seen if there is severe pulmonary hypertension

CXR:

• Left atrial enlargement
• Cardiac enlargement
• Pulmonary congestion
• Mitral valve calcification (occurs in rheumatic cases)

Echocardiography

• Assesses functional and structural impairments
• Transoesophageal echocardiogram (TOE) gives a better view

Cardiac Catheterisation
- Measures severity of heart failure