Mitral Regurgitation

Question 1

Definition

Answer 1

Retrograde flow of blood from left ventricle to left atrium during systole

Question 2

Epidemiology

Answer 2

· Affect ~5% of adults

· Mitral valve prolapse is common in young female

Question 3

Aetiology/Risk factors

Answer 3

· Broadly speaking, it is caused by mitral valve damage or dysfunction, which, in turn could be caused by any of the following:

o Rheumatic heart disease (MOST COMMON)
o Infective endocarditis
o Mitral valve prolapse
o Papillary muscle rupture or dysfunction (secondary to IHD or cardiomyopathy)
o Chordal rupture and floppy mitral valve associated with connective tissue disease (e.g. Ehlers-Danlos syndrome, Marfan’s syndrome)

Question 4

Presenting symptoms

Answer 4

· Acute MR - may present with symptoms of left ventricular failure

· Chronic MR - may be asymptomatic or present with:
o Exertional dyspnoea
o Palpitations if in AF
o Fatigue

· Mitral Valve Prolapse - asymptomatic or atypical chest pain or palpitations

Question 5

Signs on physical examination

Answer 5

· Pulse may be irregularly irregular (if in AF)

· Laterally displaced apex beat with thrusting (due to left ventricular dilation)

· Pansystolic murmur
o Loudest at apex beat
o Radiating to the axilla
o Soft S1
o S3 may be heard due to rapid ventricular filling in early diastole

· Signs of left ventricular failure in acute mitral regurgitation

· Mitral Valve Prolapse
o Mid-systolic click
o Late systolic murmur
o The click moves towards S1 when standing and away when lying down

Question 6

Investigations

Answer 6

· ECG
o NORMAL
o May show AF or p mitrale (indicates left atrial hypertrophy)

· CXR
o ACUTE mitral regurgitation may produce signs of left ventricular failure
o CHRONIC mitral regurgitation shows:
· Left atrial enlargement
· Cardiomegaly (due to LV dilation)
· Mitral valve calcification (if rheumatic heart disease is the cause)

· Echocardiography
o Performed every 6-12 months in moderate-severe MR
o Allows assessment of LV ejection fraction and end-systolic dimension