Mitral Stenosis

Question 1

Definition

Answer 1

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

Question 2

Epidemiology

Answer 2

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

Question 3

Aetiology/Risk factors

Answer 3

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

· Rare causes of mitral stenosis:
o Congenital mitral stenosis
o SLE
o Rheumatoid arthritis
o Endocarditis
o Atrial myxoma

Question 4

Presenting symptoms

Answer 4

· May be ASYMPTOMATIC

· Fatigue

· Shortness of breath on exertion

· Orthopnoea

· Palpitations (related to AF)

· Rare symptoms:
o Cough
o Haemoptysis
o Hoarseness caused by compression of left recurrent laryngeal nerve by an enlarged left atrium

Question 5

Signs on physical examination

Answer 5

· Peripheral cyanosis
· Malar flush (image)
· 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

Investigations

Answer 6

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

· CXR
o Left atrial enlargement
o Cardiac enlargement
o Pulmonary congestion
o Mitral valve calcification (occurs in rheumatic cases)

· Echocardiography
o Assesses functional and structural impairments
o Transoesophageal echocardiogram (TOE) gives a better view

· Cardiac Catheterisation
o Measures severity of heart failure