MITRAL REGURGITATION

Question 1

Acute MR- Causes (3)

Answer 1

• IHD —> papillary muscle rupture/ dysfunction
• MVP —> ruptured chordae
• IE or RHD —> ruptured chordae or cuspal perforation

Question 2

Acute MR- Pathophysiology (2)

Answer 2

• Acute MR —> sudden rise in left atrial pressure with normal LA size —> backflow into lungs —> increased pulmonary venous pressure
• No time for compensation; present with pulmonary edema or cardiogenic shock

Question 3

Chronic MR- Causes (3)

Answer 3

• MVP: myxomatous degeneration (Marfan syndrome)
• Dilated CM: annular dilatation
• RHD

Question 4

Chronic MR- Pathophysiology (3)

Answer 4

• Long-standing regurgitation —> gradually increased LA pressure accommodated by LA dilatation and increased LA compliance
• LV dilatation —> LV dysfunction
• Chronic backflow into pulmonary vessels —> pulmonary hypertension

Question 5

Symptoms (2)

Answer 5

• Volume overload of LA and LV —> dilatation and hypertrophy as compensation —> early palpitations (especially with exertion) as the initial symptom
• With time, compensation fails —> pressure increases —> symptoms of LHF (dyspnea, orthopnea, PND, fatigue, etc)

Question 6

Signs (5)

Answer 6

• Soft S1, normal S2
• S3 added sound (rapid filling of dilated noncompliant LV; ventricular gallop)
• MR PSM: pansystolic murmur (radiates to axilla)
• If the cause is MVP: mid-systolic click followed by late systolic murmur
• May have a loud palpable P2 (bc of pulmonary HTN)

Question 7

Clinical signs of severity (6)

Answer 7

• Hyperdynamic apex
• S3
• Added short mid-diastolic flow murmur
• Systolic thrill (grade 4)
• Wide split S2 (early closure of A2)
• Signs of pulmonary hypertension

Question 8

Diagnosis (4)

Answer 8

• CXR: cardiomegaly, dilated LV, pulmonary edema
• ECG: may develop A.Fib
• Echo: dilated LA and LV, decreased LV function
• Doppler: severity of regurgitation

Question 9

Treatment (3)

Answer 9

1- Mild asymptomatic: follow-up echo and clinical examination
2- Medical therapy:
- ACE inhibitors to decrease afterload (for LVF)
- Diuretics for symptomatic relief
- If A.Fib —> lifelong warfarin
3- Surgery:’
- Acute MR —> emergency surgery: valve replacement
- Chronic MR —> repair is better than replacement
- Indication for surgery: symptomatic, severe and EF >30% and end-diastolic diameter <55mm
- Preserved EF with A.Fib or pulmonary hypertension