Station 3.4: Mitral incompetence

Question 1

Clinical signs

What are the clinical signs of Mitral incompetence?

Mitral incompetence

This patient has been short of breath and tired. Please examine his cardiovascular system.

Answer 1

• Scars: lateral thoracotomy (valvotomy)
• Pulse: AF, small volume
• Apex: displaced and volume loaded
• Palpation: thrill at apex
• Auscultation: Pan-systolic murmur (PSM) loudest at the apex radiating to the axilla. Loudest in expiration. Wide splitting of A2P2 due to the earlier closure of A2 because the LV empties sooner. S3 indicates rapid ventricular filling from LA, and excludes significant mitral stenosis
• Pulmonary oedema
• Cause: signs of endocarditis (see pages 45–46)
• Severity: left ventricular failure and atrial fibrillation (late). Not murmur intensity
• Other murmurs, e.g. ASD (see page 60)

Question 2

Discussions

What are the causes of Mitral incompetence?

Mitral incompetence

This patient has been short of breath and tired. Please examine his cardiovascular system.

Answer 2

• Congenital (association between cleft mitral valve and primum ASD)
• Acquired:
  ~~~
  —————-|– Acute ———–|——- Chronic – |
  Valve leaflets – |– Bacterial endocarditis–|–Myomatous degeneration (prolapse)

———————–|——————-|—Rheumatic

———————–|——————-|—Connective tissue diseases

———————–|——————-|–Fibrosis (fenfluramine/pergolide)

Valve annulus –|————–| –Dilated left ventricle (functional MR)

—————————-|—————-|– Calcification
Chordae/papillae –|– Rupture |– Infiltration, e.g. amyloid

—————————–|—————|———— Fibrosis (post‐MI/trauma)

Question 3

Discussions - investigations

What investigations are required for Mitral incompetence?

Mitral incompetence

This patient has been short of breath and tired. Please examine his cardiovascular system.

Answer 3

• ECG: p‐mitrale, atrial fibrillation and previous infarction (Q waves)
• CXR: cardiomegaly, enlargement of the left atrium and pulmonary oedema
• TTE/TOE:
  Severity: size/density of MR jet, LV dilatation and reduced EF
  Cause: prolapse, vegetations, ruptured papillae, fibrotic restriction and infarction

Question 4

Discussions - Management

How would you manage Mitral incompetence?

Mitral incompetence

This patient has been short of breath and tired. Please examine his cardiovascular system.

Answer 4

• Medical
  ⚬ Anticoagulation for atrial fibrillation or embolic complications
  ⚬ Diuretic, β‐blocker and ACE inhibitors
• Percutaneous: mitral clip device for palliation in inoperative cases of mitral valve
  prolapse
• Surgical
  ⚬ Valve repair (preferable) with annuloplasty ring or replacement
  ⚬ Aim to operate when symptomatic, prior to severe LV dilatation and dysfunction

Question 5

Discussions - Prognosis

What is Mitral valve prolapse?

Mitral incompetence

This patient has been short of breath and tired. Please examine his cardiovascular system.

Answer 5

• Common (5%), especially young tall women
• Associated with connective tissue disease, e.g. Marfan’s syndrome and HOCM
• Often asymptomatic, but may present with chest pain, syncope and palpitations
• Small risk of emboli and endocarditis
• Auscultation
  ⚬ Mid-systolic ejection click (EC). Pan-systolic murmur that gets louder up to A2.
  ⚬ Murmur is accentuated by standing from a squatting position or during the straining phase of the Valsalva manoeuvre, which reduces the flow of blood through the heart.