Mitral Regurgitation

Question 1

What are the indications for valve replacement in mitral regurgitation?

Answer 1

Signs of left ventricular dysfunction
- Reduced EF < 60% or < 55% (even in the absence of symptoms)
- Dilated left ventricle

Question 2

What are the causes of mitral regurgitation? (11)
- M: MR ABCDE ACTS

Answer 2

Chronic
1. Mitral valve prolapse
2. Rheumatic fever/heart disease
3. AMI, IHD (papillary muscle dysfunction)
4. Big heart (cardiomyopathy - DCM, HOCM, ICMP)
5. Connective tissue disease (Marfan’s, Ehlers Danlos)
6. Degenerative calcification (elderly)
7. Endocarditis
8. Aortic stenosis or left ventricular dilatation causes
9. Congenital (cTGA, partial AV canal, ostium primum atrial defect)

Acute
10. Infective endocarditis
11. MI (rupture of chorade tendinae)
12. Trauma
13. Surgery: mitral valvotomy (presence of thoracotomy scar)

Question 3

What are the clinical signs of severe mitral regurgitation? (9)

Answer 3

1. Atrial fibrillation is common
2. Soft first heart sound (S1)
3. Third heart sound (S3)
4. Thrusting and displaced apex beat (volume overload, dilatation)
5. Precordial thrill
6. Widely split S2 (early AV closure, delayed PV closure from RVH)
7. Short MDM present (functional stenosis due to large volume regurgitation)
8. Signs of pulmonary hypertension
9. Signs of pulmonary congestion

Question 4

What are the differential diagnoses for pansystolic murmur? (3)

Answer 4

1. MR (usually loudest at apex, radiates to axilla, loudest in expiration)
2. TR (left lower parasternal edge, loudest in inspiration)
3. VSD (left lower parasternal edge)

Question 5

How would you investigate a patient with mitral regurgitation?
- ECG (4)
- CXR (4)
- TTE
- Coronary angiogram

Answer 5

ECG
- LA hypertrophy, dilatation (P mitrale: bifid P, negative P)
- LVH (Sokolow Lyon criteria: SV1 +RV5 > 35mm)
- Atrial fibrillation
- Pulmonary hypertension (RV strain, P pulmonale, RAD, RBBB)

CXR
- LA enlargement (double right heart border)
- Cardiomegaly
- Pulmonary congestion
- Prominent pulmonary artery

Echo
- Mechanism of mitral regurgitation
- Assess severity: LVEF < 60%, LV ES diameter > 45mm
- Complications (IE)

Coronary angiography
- Exclude coronary artery disease
- Right heart catheterisation to estimate pulmonary artery pressure

Question 6

How would you manage a patient with mitral regurgitation?

Answer 6

Asymptomatic
Education
Endocarditis prophylaxis
Serial echocardiogram

Symptomatic
Rate and rhythm control and anticoagulation if in atrial fibrillation
Management of heart failure
Consideration for surgery if moderate symptoms despite medical therapy and EF is adequate

Question 7

How do you grade the severity of mitral regurgitation?
- Clinically

Answer 7

Clinically
Mild - no pulmonary hypertension
Moderate - pulmonary hypertension
Severe - left heart failure, S3

Question 8

What are the congenital conditions associated with MR?

Answer 8

1. Corrected transposition of great arteries (cTGA)
2. Partial AV canal (PAVC)
3. Ostium primum atrial septal defect (OPASD) - cleft mitral valve

Question 9

What causes third heart sound (S3)

Answer 9

Rapid filling of left ventricle by large volume of blood from left atrium during early diastole

Question 10

What is jerky pulse?
Why is there jerky pulse in MR?

Answer 10

Pulse sharp and abbreviated
Regurgitant leak into left atrium causes lack of sustained forward stroke volume and reduced systolic ejection time

Question 11

Severe MR can present with PSM and MDM
How do you differentiate MR vs MS?

Answer 11

MS: opening snap, longer EDM murmur, loud S1
MR: associated with S3, soft S1

Question 12

How do you differentiate between MR and TR?
- Site, radiation, maneuvre, apex beat, pulse character, JVP

Answer 12

Question 13

How do you differentiate between MR and VSD?
- Site, pitch, S1

Answer 13

Question 14

What is the pathophysiology of MR?

Answer 14

1. LV overload and compensatory LV dilatation
   - Decompensation: heart failure, risk of sudden death
2. Regurgitation into LA -> LA enlargement and overload
   - AF, pulmonary hypertenion

Question 15

What are the clinical features of MR? (9)

Answer 15

1. Jerky pulse (sharp upstroke, small amplitude)
2. AF with stroke or anticoagulation
3. Deviated thrusting apex beat
4. Left parasternal heave (RVH)
5. Soft or absent S1
6. S3
7. Pansystolic murmur, high pitch, over mitral area radiating to axilla
8. Loud P2 (pulmonary hypertension)
9. Bibasal crepitations (pulmonary congestion)

Question 16

What are the indications for surgery in MR?

Answer 16

Symptomatic
EF < 60%
LV end systolic dimension > 45mm

Question 17

What are the types of surgery in MR?

Answer 17

Mitral valve repair if technically feasible
Mitral valve replacement if technically not feasible but EF > 30%