Mitral stenosis

Question 1

Define mitral stenosis.

Answer 1

Diastolic murmur - heard at the apex.

The valve does not open as wide as it should, restricting the flow of blood through the heart.

Question 2

Who is most affected?

Answer 2

· More common in women.

· First symptoms usually appear in 40-50 year olds.

Question 3

What is the pathophysiology of mitral stenosis?

Answer 3

· As the valve orifice becomes reduced, flow between the left atrium and ventricle is impeded.

· The pressure in the left atrium remains higher than that of the left ventricle.

· Restricting flow causes:

• Increased left atrial pressure is referred to the lungs, leading to congestion.
• The restricted orifice limits filling of the left ventricle, thereby limiting cardiac output&raquo_space;> producing symptoms mimicking LHF.

· Pulmonary vasoconstriction adds to right ventricular pressure overload, and pulmonary hypertension develops.

Question 4

If patients have advanced symptoms and/or pulmonary hypertension, what is the average survival time?

Answer 4

Poor at 3 years.

Question 5

What is the most common cause of mitral stenosis?

Answer 5

Rheumatic fever leading to rheumatic heart disease is the cause in 95% of cases.

Question 6

List the possible risk factors?

Answer 6

· Streptococcal infection.
· Female.
· Rheumatic fever history.

Question 7

What are the common signs and symptoms of a patient presenting with mitral stenosis?

Answer 7

· Malar flush. 
· Dizziness.
· Dyspnoea on exertion - may progress to orthopnoea and PND. 
· Cough and haemoptysis. 
· CAD.
· Pulse - small volume and AF. 
· Pulmonary hypertension. 
· Murmur heard best in left lateral position with the bell of the stethoscope in expiration.

Question 8

What investigations would help diagnose mitral stenosis?

Answer 8

· ECG.
· CXR - double right heart border indicating an enlarged left atrium
· ECHO.

Question 9

What definitive test confirms the diagnosis of mitral stenosis and quantitates the severity of the disease?

Answer 9

ECHO.

Question 10

On an ECHO, a thickened anterior mitral valve leaflet often appears as what shape?

Answer 10

Hockey stick-shape.

Question 11

Suggest some differential diagnoses.

Answer 11

· Inflow obstruction - hypertrophic cardiomyopathy or left atrial myxoma.
· Aortic regurgitation.
· Tricuspid stenosis.

Question 12

What are the current treatment options for mitral stenosis?

Answer 12

· Balloon valvotomy, valve repair or replacement.
· Diuretics.
· Anti-coagulants.
· Otherwise no treatment needed.

Question 13

List some complications that may arise.

Answer 13

· AF.
· Stroke.
· Infective endocarditis.