Mitral valve disease (mitral stenosis & regurg)

Question 1

What is mitral stenosis?

Answer 1

Narrowing of the orifice of the mitril valve, impeding blood flow

Symptoms begin when orifice <2cm²

Question 2

Outline the cause, pathophysiology, symptom & signs for Mitral stenosis

Answer 2

20-yrs post Rheumatic Heart Disease

• Thickening & immobility of the valve leaflets **⇒ **obstruction of blood flow
  
  • ​Loud palpable S1
  • Opening snap
  • Rumbing mid-diastolic murmur
    
    • Apex with bell + lying on left + expiration
    • Pre-systolic accentuation
  • Low-volume pulse
• ↑LA pressure ⇒ eventual dilatation
  
  • Atrial fibrilation
  • **Thromboembolism **⇒ stroke etc
• ⇒ Pulmonary hypertension
  
  • Pulmonary oedema
  • ⇒ vasoconstriction ⇒** Haemoptysis**
• ⇒ RV hypertrophy
  
  • Parasternal heave
  • ​⇒ dilatation ⇒ RH failure

Symptoms (when orifice <2cm²);

• Dyspnoea, orthopnea, PND
• Chest pain, palpitations

Question 3

What investigations would you do for mitral stenosis?

Answer 3

• ECG;
  
  • Enlarged RV (V₁-V₃ - large QRS)
  • Enlarged LA (V₁-V₃ - S P-wave)
  • AF
  • P-mitrale (broad notched P wave in V1+ due to atrial overload)
• CXR;
  
  • LA enlargement (double shadow in right cardiac silhouette)
  • Pulmonary oedema
  • Mitral valve calcification
• Echocardiography; diagnostic!
  
  • ​Large LA
  • Stenosis in valve & large pressure gradient between LA & LV

Question 4

How would you manage mitral stenosis?

Answer 4

• Atrial fibrilation
  
  • Warfarin
  • Control rate
• Diuretics
  
  • ​Dec preload & pulmonary venous congestion
• Balloon valvuloplasty
  
  • ​If pliable & not calcified
  • Otherwise valve replacement

Question 5

What is mitral regurgitation?

Answer 5

Mitral valve does not close properly during ventricular systole causing regurgitation of blood back into left atrium

Question 6

Outline the cause, pathophysiology, symptom & signs for Mitral regurgitation

Answer 6

Causes;

• Mitral valve prolapse
• Chordae tendineae/ papillary muscle
• Acute cause: Infective endocarditis

Pathophysiology;

• **Blood flow back into LA **during systole
  
  • Apex pansystolic murmur ⇒ axilla
  • Quiet S₁ [valve doesnt properly shut]
• Acute - regurgitated blood causes
  
  • LA pressure increases ⇒ pulmonary congestion
    
    • Loud palpable P2
    • Pulmonary oedema
    • CCF
  • **LV volume overload **[↑blood: normal + re-entering regurgitated] ⇒ ↑SV [frank]
• Chronic [compensated ⇒ uncompensated & CCF]
  
  • **LV hypertrophy **[maintain output with volume overload] ⇒ dilatation & failure
    
    • ​Displaced hyperdynamic apex
  • LA dilatation [↓pulmonary pressure]
    
    • AF
• Symptoms
  
  • ​Dyspnoea, orthopnea, PND

Question 7

What investigations would you do for mitral regurg?

Answer 7

• ECG
  
  • Atrial fibrilation
  • P-mitrale (broad notched P wave in V₁+ due to atrial overload)
• CXR
  
  • ​Big LA & LV
  • Mitral valve calcification
  • Pulmonary oedema
• Echo
• Cardiac catheterization; diagnostic

Question 8

How would you manage mitral regurg?

Answer 8

• Atrial fibrilation
  
  • Warfarin
  • Control rate
• Diuretics
  
  • ​Dec preload & pulmonary venous congestion
• Balloon valvuloplasty
  
  • ​If pliable & not calcified
  • Otherwise valve replacement