๐ก Key Point: Mitral regurgitation (MR) = backward flow of blood from LV โ LA during systole.
This leads to LA + LV volume overload, pulmonary congestion, AF, and eventual HF if untreated.
๐ About
- Definition: Retrograde systolic flow from LV โ LA due to incomplete valve closure.
- Acute MR: ๐จ Sudden, no time for LA adaptation โ pulmonary oedema + acute HF.
- Chronic MR: ๐ฐ๏ธ Gradual; LA dilates & compensates โ later LV failure.
๐งฌ Pathophysiology
- Volume overload: Regurgitant jet โ LA pressure & volume โ LA dilatation, eccentric LV hypertrophy.
- Acute MR: Sudden rise in LA pressure โ pulmonary oedema, cardiogenic shock.
- Chronic MR: Initially well-tolerated โ progressive LV dysfunction, HF, AF.
๐ Causes
- ๐ Mitral Valve Prolapse (MVP): Most common in developed world.
- ๐ Rheumatic Heart Disease: Post-strep scarring & fusion (still common globally).
- โค๏ธ Ischaemic Heart Disease: Papillary muscle rupture or dysfunction post-MI.
- ๐ฆ Infective Endocarditis: Leaflet/chordal destruction โ acute/chronic MR.
- โ๏ธ Degenerative Valve Disease: Annular dilatation, calcification.
- ๐ Cardiomyopathy: Dilated/HCM distorts valve apparatus.
- ๐ถ Congenital: Cleft/parachute valve anomalies.
- ๐งฌ Connective Tissue: Marfan, Ehlers-Danlos, OI.
- ๐ฉธ Trauma: Papillary/chordal rupture after chest injury.
๐ฉบ Clinical Features
- Symptoms: Palpitations (AF), exertional dyspnoea, fatigue, orthopnoea/PND if severe.
- Signs:
- ๐ถ Pansystolic murmur @ apex โ axilla.
- ๐ S3 gallop (volume overload).
- Diffuse, displaced apex beat (LV dilatation).
- Soft S1, loud P2 (pulmonary HTN).
- ยฑ Mid-diastolic rumble if large regurgitant volume.
๐งช Investigations
- Bloods: FBC, U&E; cultures if IE suspected.
- ECG: AF, LA enlargement (P mitrale), LVH.
- CXR: LA enlargement, pulmonary oedema, cardiomegaly.
- Echocardiography (TOE best detail): Valve anatomy, regurgitant jet, LA/LV size, pulmonary pressures.
- Cardiac cath: Confirms MR; PCWP shows giant V waves.
โ๏ธ Management
- ๐ Medical:
โ Diuretics โ relieve pulmonary congestion.
โ ACEi/ARB โ reduce afterload.
โ Rate control in AF (ฮฒ-blockers, digoxin, Caยฒโบ blockers).
โ Anticoagulation in AF (per CHAโDSโ-VASc).
- ๐ง Surgical:
โ Valve repair preferred (better survival, LV preservation).
โ Valve replacement if not repairable (mechanical vs bioprosthetic).
- ๐ฉน Percutaneous:
โ MitraClip for high-risk surgical patients.
โ TMVR emerging option.
- โก AF Management:
โ Rate control, rhythm control, anticoagulation.
- ๐ Monitoring:
โ Serial echo (LV function, LA size, pulmonary HTN).
โ Clinical: symptoms, functional class.
- ๐ฑ Lifestyle:
โ Moderate exercise.
โ Low-salt diet.
โ Stop smoking, manage HTN, lipids.
๐ Teaching Pearl
๐ก Think MR = pansystolic apex murmur โ axilla.
๐ง Acute MR = pulmonary oedema & shock.
๐ฐ๏ธ Chronic MR = AF + heart failure later.
Repair > Replace whenever feasible.
