Mitral regurgitation

Question 1

What is mitral regurgitation?

Answer 1

Mitral regurgitation is when an incompetent mitral valve allows blood to lead back through during systolic contraction of the left ventricle. It results in CCF because the leaking valve causes a reduced ejection fraction and a backlog of blood that is waiting to be pumped through the left side of the heart.

Question 2

What are the risk factors for mitral regurgitation?

Answer 2

• Mitral valve prolapse - may result from abnormal elasticit
• hx of rheumatic fever
• infective endocarditis
• hx of cardiac trauma
• congenital heart disease
• IHD/MI
• left ventricular systolic dysfunction
• hypertrophic cardiomyopathy
• anorectic/dopaminergic drugs - or serotonergic drugs such as ergotamine, pergolide, and cabergoline have been shown to cause MR.

Question 3

What are the causes of mitral regurgitation?

Answer 3

• Idiopathic weakening of the valve with age
• Ischaemic heart disease
• Infective endocarditis
• Rheumatic Heart Disease
• Connective tissue disorders such as Ehlers Danlos syndrome or Marfan syndrome

Other: Myxomatous degeneration of the mitral leaflets or chordae tendineae, mitral valve prolapse,

Question 4

What does mitral regurgitation sound line? Where is it best heard?

Answer 4

Pan-systolic, high pitched ‘whistling’ mumur - due to high velocity of blood flow through the leaky valve.

Radiates to left axilla - S3 may be heard.

Question 5

What are the symptoms of mitral regurgitation?

Answer 5

Mild to moderate disease can be asymptomatic for many years; with progression of the disease there is hypertrophy, elongation of myocardial fibres and increased LV and ED volume.

• Exertional dyspniea, decreased exercise tolerance
• Palpitations
• Lower extremity oedema
• Fatigue
• Pulmonary congestion –> orthopnoea and paroxysmal nocturnal dyspnoea

Question 6

What are the findings on examination?

Answer 6

Physical findings =

• Displaced, volume-loaded apex beat
• Soft S1
• S3

Question 7

What are the other pansystolic murmurs?

Answer 7

• •Tricuspid regurgitation
• •Mitral regurgitation
• •Ventricular Septal Defect (VSD)

Question 8

What investigations would you do for mitral regurgitation?

Answer 8

• Transthoracic ECHO with colour Doppler flow - best for identifying presence, severity and suitability of repair or replacement.

Other:

• ECG - routine screen for AF or prior infarction
• Left cardiac catheterisation - to check for CAD
• CXR - LA and LV hypertrophy, mitral valve calcification, cardiomegaly, pulmonary congestion (upper lobe diversion)
• Bloods: FBC, U&Es, glucose, lipids, culture

Question 9

What is the anatomy of the mitral valve?

Answer 9

The mitral valve apparatus consists of anterior and posterior leaflets, chordae tendineae, anterolateral and posteromedial papillary muscles, and mitral annulus. Any aberrations of the mitral valve apparatus, due to mechanical, traumatic, infectious, degenerative, congenital, or metabolic causes, may lead to mitral regurgitation (MR).

Question 10

Which of these are signs of MR?(3)

• Atrial fibrillation
• Dyspnoea
• Pansystolic murmur radiating to the axilla
• Slow rising pulse

Answer 10

Top 3

• Symptoms of MR – often presents with dyspnoea, fatigue, palpitations.
• Signs – atrial fibrillation, displaced hyperdynamic apex, pansystolic murmur at the apex radiating to the axilla.
• The more severe the larger the ventricle.

Question 11

Where might these patients have a scar?

Answer 11

Valvotomy scar under the left breast