Mitral Stenosis

Question 1

What is mitral stenosis?

Answer 1

Mitral stenosis is a narrowing of the mitral valve orifice.

Question 2

What is the main cause of mitral stenosis?

Answer 2

Rheumatic heart disease

Question 3

What are the risk factors for mitral stenosis?

Answer 3

• Streptococcal infection
• Female sex
• History of rheumatic fever

Question 4

What are the signs of mitral stenosis?

Answer 4

• Malar flush on cheeks
• Opening snap of auscultation
• Rumbling mid-diastolic murmur
• Loud p₂
• Neck vein distension
• Tapping, non-displaced apex beat

Question 5

What are the symptoms of mitral stenosis?

Answer 5

• Dyspnoea
• Orthopnea
• Paroxysmal nocturnal dyspnoea
• Haemoptysis
• Dysphagia
• Fatigue
• Palpitations
• Peripheral oedema

Question 6

What investigations should be ordered for mitral stenosis?

Answer 6

• ECG
• CXR
• Echocardiogram
• Cardiac catheterisation

Question 7

Why investigate using ECG?

Answer 7

This non-specific test is performed at baseline and again if there is a change in the patient’s rhythm.

Atrial fibrillation, left atrial enlargement and right ventricular hypertrophy.

Question 8

Why investigate using CXR?

Answer 8

Test ordered at baseline and again if there is a major change in symptoms.

Double right heart border indicating an enlarged left atrium, prominent pulmonary artery, pulmonary oedema and Kerley B lines.

Question 9

Why investigate using echocardiogram?

Answer 9

An echocardiogram is the definitive test to confirm the diagnosis and to quantitate the severity of the disease.

Shows hockey stick-shaped mitral deformity.

Question 10

Why investigate using cardiac catheterisation?

Answer 10

Used to calculate valve area. Only performed if inadequate information is available from echocardiography and surgical correction is planned.

Shows high left atrial pressure, low left ventricular pressure and low cardiac output.

Question 11

What are the definitive treatment options for mitral stenosis? And who should this be offered to?

Answer 11

Mitral stenosis is a mechanical obstruction to inflow of the left ventricle. As such, definitive therapy requires a mechanical solution by percutaneous balloon valvotomy, surgical mitral valve repair or valve replacement.

Definitive therapy should be offered to patients with severe symptomatic disease who are unlikely to benefit from medical therapy alone, and may be considered in some patients with severe asymptomatic disease.

Question 12

What is the benefit of diuretic treatment in mitral stenosis?

Answer 12

Decrease preload and pulmonary venous congestion.

Question 13

What are the complications of mitral stenosis?

Answer 13

• Atrial fibrillation
• Stroke

Question 14

What differentials should be considered for mitral stenosis?

Answer 14

1. Left atrial myxoma
2. Unexplained atrial fibrillation

Question 15

How does mitral stenosis and left atrial myxoma differ?

Answer 15

Differentiating signs and symptoms:

• This left atrial tumour may obstruct the mitral orifice and mimic the signs and symptoms of mitral stenosis

Differentiating investigations:

• Echocardiography clearly shows a mass lesion

Question 16

How does mitral stenosis and unexplained atrial fibrillation differ?

Answer 16

Differentiating signs and symptoms:

• At rapid heart rates the signs of mitral stenosis may be difficult to discern

Differentiating investigations:

• Echocardiography excludes mitral stenosis