Mitral regurgitation

Question 1

What is the definition of a mitral valve?

Answer 1

1. The mitral valve is located between the left atrium and left ventricle
2. Mitral regurgitation occurs when blood leaks back through the mitral valve on systole

Question 2

What is the pathophysiology of mitral regurgitation?

Answer 2

1. Regurgitation of the blood from the ventricle back into the left atria
2. Leads to less efficient heart as less blood is pumped through the body with each contraction

Question 3

What are the causes of Mitral Regurgitation?

Answer 3

1. Papillary muscle rupture -

• 2nd to coronary artery disease or post MI
  If the papillary muscles are affected by cardiac insult - mistral valves may be unable to close

2. Infective endocarditis

• Vegetations from the organisms colonising the heart - grow on the mitral valve
  Prevents from closing properly

3. Rheumatic fever

-Inflammation of the valves and therefore results in mitral regurgitation

4. Left sided heart failure

Dilation of the left ventricle stretches the mitral valve and blood leaks back into left atrium

Question 4

What are the risk factors?

Answer 4

1. IV drug use
2. Congenital bicuspid valve
3. Diabetes, high blood pressure and smoking

Question 5

What are the complications of mitral regurgitation?

Answer 5

1. Pulmonary congestion, oedema
   - Constant elevation in blood volume, pressure in left atrium causes dilation
   Blood backs into pulmonary circulation
2. Pulmonary hypertension

Extra blood volume, pressure in left ventricle backs into lungs causing higher pressure in the pulmonary circulation

3. Right sided heart failure

Back up of blood in left atrium, lung -leads to pulmonary hypertension - right sided heart failure

4. Dilted atrium - leads to Atrial fibrillation
5. Dysphagia
   2nd to dilated atrium compressing the oesophagus

Question 6

What are the clinical features of mitral regurgitation?

Answer 6

Shortness of breath, oedema
Fatigue

Question 7

What are the investigations of Mitral regurgitation?

Answer 7

1. ECG : broad P wave, indicative of atrial enlargement
2. CXR : Cardiomegaly with an enlarged left atrium and ventricle
3. Echocardiography is crucial to diagnosis and to assess severity

Question 8

What is the management of mitral regirgitation?

Answer 8

1.Medical management :
- involves nitrates, diuretics, positive inotropes and an intra-aortic balloon pump to increase cardiac output

2. If patients are in heart failure, ACE inhibitors may be considered along with beta-blockers and spironolactone
3. Surgery if severe