Mitral valve disease (CVS)

Question 1

Define mitral stenosis

Answer 1

This is the narrowing of the mitral valve, reducing blood flow to the left ventricle. This leads to increased pressure in LA, pulm vasculature, and right heart

Question 2

What is the main cause of mitral stenosis?

Answer 2

Rheumatic fever

Question 3

What is the pathophysiology of mitral stenosis?

Answer 3

Normally, mitral valve opens during diastole to allow left ventricular filling.
In mitral stenosis, the thickened scarred mitral valve reduces the bloodflow through the valve into the LV in diastole. This leads to a reduced end-diastolic volume in the LV and increases the vol of blood in the LA and this leads to atrial dilatation (predisposing to atrial fibrillation), pulmonary congestion and ultimately right heart failure.

Question 4

What are the rarer causes of mitral stenosis?

Answer 4

Mitral annular calcification (age related), Congenital MS (rare), Mucopolysaccharidosis, carcinoid, systemic disease like SLE or rheumatic arthritis

These are seen in developed countries

Question 5

What are the risk factors for mitral stenosis?

Answer 5

Ageing, radiation, strep a, other causes

Question 6

What are differentials of mitral stenosis?

Answer 6

Mitral regurg, Aortic stenosis, Left atrial myxoma

Question 7

What is the aetiology of rheumatic heart disease causing mitral stenosis (simple)?

Answer 7

The body produces antibodies to target the streptococcal antigens that occur in rheumatic fever. These antibodies also attack valvular tissue (autoimmune molecular mimicry) leading to valvular disease.

Question 8

What are the symptoms of mitral stenosis?

Answer 8

Typically asymptomatic until advanced stenosis
SOB, Haemoptysis, malar flush, palpitations (if AFib happens), chest pain

Question 9

What are the clinical signs of mitral stenosis?

Answer 9

• Irregularly irregular pulse (AF)
• Elevated JVP
• Right ventricular heave
• Inspiratory crepitations (pulmonary oedema) and other signs of right HF
• Low volume pulse
• Loud S1/S2
• Mid-to-late diastolic murmur
  
  • low pitch rumble
  • most prominent at apex
  • loudest on expiration
  • heard best on pt lying left and
    using bell
• Early diastolic murmur (only if pulmonary regurgitation is present, secondary to pulmonary HTN)

Question 10

What are the investigations for mitral stenosis?

Answer 10

Echo - this makes the diagnosis as we see degree of stenosis and impairment of vent filling
CXR - may show pulm oedema and LA enlargement
ECG - p mitrale, right vent hypertrophy, right axis deviation, Afib
Cardiac MRI

Question 11

When do symptoms start with mitral stenosis area wise?

Answer 11

Typically when falls below 1.5cm^2

Question 12

What is the management of asymptomatic mitral stenosis?

Answer 12

Observe/monitor - regular follow up echocardiograms to assess progression

Question 13

What is the management of mitral stenosis with the complication of Afib?

Answer 13

Anticoagulation - warfarin for mod-severe MS. Maybe consider DOACs for mild MS.

Question 14

What is the management of symptomatic mitral stenosis?

Answer 14

• Balloon valvuloplasty (if valve is pliable and not calcified)
• Percutaneous mitral balloon valvotomy (for moderate)
• Open valve surgery: Either a Commissurotomy or Valve replacement (for severe disease who are not too high risk for surgery, but not candidates for percutaneous)

Question 15

What are the complications of mitral stenosis?

Answer 15

Afib, pulmonary hypertension, dilated left atrium

Question 16

Define mitral regurgitation

Answer 16

Backflow of blood into the left atrium during systole due to an incompetent mitral valve
It is common.

Question 17

What are the common causes of mitral regurg?

Answer 17

Mitral valve prolapse
Degenerative valve disease (age)
MI with secondary papillary muscle rupture
Infective endocarditis
Rheumatic heart disease

Question 18

What are the differentials of mitral regurg?

Answer 18

Aortic stenosis, tricuspid regurg, aortic regurg

Question 19

What are the clinical features of acute mitral regurg?

Answer 19

This is an emergency.
SOB, exertional dyspnea, fatigue, weakness, cardiogenic shock, pulm oedema

Question 20

What are the clinical symptoms of chronic mitral regurg?

Answer 20

Mild to moderature - asymptomatic until Left HF leading to pulmonary hypertension or symptomatic atrial fibrillation (AF)
Then we see symptoms such as exertional dyspnea and fatigue occuring due to the pulm hypertension.

Question 21

What are the clinical signs of mitral regurg?

Answer 21

• Pansystolic ‘blowing’ murmur
  
  • Loudest at apex
  • Radiates to axilla
  • Louder on expiration
  • Louder on rolling to left
• Absent / quiet S1
• IF pt in decompensated HF
  
  • Bi-basal lung crepitations
  • Raised JVP
  • S3 / S4
  • Peripheral / sacral oedema

Question 22

What are the investigations for sus mitral regurg?

Answer 22

Echo - diagnostic/definitive
ECG - broad P wave/p mitrale due to LA enlargement
CXR - pulm oedema and LA enlargement

Question 23

What is the management of acute mitral regurg incl if complications?

Answer 23

This is an emergency with often shock and flash pulm oedema.

Nitrates, diuretics, positive inotropes, and an intra aortic balloon

If has HF - consider ACEi and BB

If acute and v severe -> surgery (repair>replacement)

Question 24

What are the complications of mitral regurg?

Answer 24

HF
Afib leading to thromboembolism

Question 25

What is the management of chronic mitral regurg?

Answer 25

Most chronic cases remain asymptomatic and stable and may not require treatment at all.
If has asymptomatic MR they should undergo regular follow-up echocardiography.