Mitral regurgitation

Question 1

Define mitral regurgitation.

Answer 1

Some blood flows the wrong way in the heart because the mitral valve does not close properly.

Pan-systolic murmur:

• Heard throughout systole, merging with the 2nd heart sound.
• Heard over the apex.

Can be acute or chronic.

Question 2

Is mitral regurgitation more common in men or women?

Answer 2

Incidence is equal in men and women.

Question 3

What is the pathophysiology of mitral regurgitation?

Answer 3

· Chronic MR can be mild / moderate and can be asymptomatic for many years.
· With progression to severe, eccentric hypertrophy and elongation of myocardial fibres, increased left ventricular end-diastolic volume increases.
· This is compensatory to maintain cardiac output.

Question 4

What is the prognosis of mitral regurgitation?

Answer 4

Mortality is lower with mitral valve repair than with replacement.

Question 5

What is the aetiology of mitral regurgitation?

Answer 5

· Rheumatic fever.
· Floppy valve leaflets.
· Rupture after an inferior MI. 
· Cardiomyopathy.  
· Connective tissue disorders - SLE, RA, AS, EDS.

Question 6

What are the most common risk factors of mitral regurgitation?

Answer 6

· Mitral valve prolapse. 
· History of rheumatic heart disease.
· Infective endocarditis. 
· History of MI/Congenital heart disease/IHD. 
· Hypertrophic cardiomyopathy.

Question 7

What are the typical presenting signs and symptoms?

Answer 7

· Progressive exertional dyspnoea.
· Palpitations.
· Fatigue. 
· Lower extremity oedema. 
· Pulmonary oedema if severe. 
· Fine bibasilar crackles if pulmonary oedema due to LV overload. 
· Parasternal heave secondary to left atrial enlargement.
· Jerky pulse, possible AF.

Question 8

What investigations would you request if you suspected a patient had mitral regurgitation?

Answer 8

· ECG.

· ECHO.

Question 9

List some differentials.

Answer 9

· ACS. 
· Infective endocarditis (IE). 
· Mitral stenosis. 
· Aortic stenosis.
· Atrial myxoma.

Question 10

What is the treatment option for acute mitral regurgitation?

Answer 10

1st line - Emergency surgery:

• Annuloplasty or mechanical valve and anticoagulation or bioprostheses.
• Adjunct - Preoperative diuretics.

Question 11

What is the treatment option for chronic mitral regurgitation?

Answer 11

· ACE inhibitors.
· Beta-blockers.
· Surgery.

Question 12

Suggest some possible complications.

Answer 12

· AF - occurs as a result of left atrial enlargement.
· Pulmonary hypertension - occurs as a result of left-sided failure and pressure overload.
· LV dysfunction and CHF.