Mitral Regurgitation

Question 1

What is mitral regurgitation?

Answer 1

Backflow through the mitral valve during systole

Question 2

What are the causes of MR?

Answer 2

Primary - Affects the valve itself

• Degenerative calcification
• Infective endocarditis
• Rheumatic heart disease
• Congenital anormalities
• Medication eg ergotamine, bromocriptine, pergolide

Secondary - Result of left ventricle

• Ischaemia due to MI, leads to LV remodelling and impairs valve ability to close
• Dilated and hypertrophic cardiomyopathy

Question 3

What are the causes of acute MR?

Answer 3

Usually results from primary causes of MR

• The papillary muscle rupture causes valvular incompetence in MI
• Ruptured chondae tendinae also

Question 4

What is the pathophysiology causing symptoms in MR?

Answer 4

1. In ventricular systole, blood flows into the LA
2. This increases LA pressure and reduces the ejection fraction, allowing compensatory mechanisms to occur over time
   Mechanisms -
   - LV dilates to maintain a large SV so larger EF
   - LA dilates to prevent rise in atrial and therefore pulmonary pressure

Question 5

What is decompensated MR?

Answer 5

• When compensation cannot maintain normal cardiac function, so remodelling becomes pathological
• Heart fails, EF falls and pulmonary pressures rise

Question 6

What murmur describes MR?

Answer 6

Pansystolic murmur at apex, radiating to the axilla

Question 7

What are the symptoms of acute MR?

Answer 7

• Inadequate CO so pulmonary oedema
• Shock
• Dyspnoea
• Tachycardia

Question 8

What are the symptoms of chronic MR?

Answer 8

• Heart failure symptoms

Question 9

What signs, other than a murmur suggest MR?

Answer 9

• Displaced apex beat
• Systolic thrill
• Soft S1
• Signs of heart failure

Question 10

What investigations are required?

Answer 10

Bedside
- ECG (LA enlargement called p mitrale a broad notched wave with negative V1, LV hypertrophy, AF sometimes)

Imaging -
CXR
Echocardiogram (diagnostic)

Question 11

What will a CXR show in MR?

Answer 11

• LA and LV enlargement (double right heart boarder sign)

- Pulmonary oedema

Question 12

What is the management for MR?

Answer 12

Medical -
- ACEi, BB, spironolactone aka treat the heart failure

Surgical -
- Repair or replace valve

If secondary MR, surgical intervention may not improve outcomes