Makindo Medical Notes

💡 Key Point: Mitral regurgitation (MR) = backward flow of blood from LV → LA during systole. This leads to LA + LV volume overload, pulmonary congestion, AF, and eventual HF if untreated.

📖 About

• Definition: Retrograde systolic flow from LV → LA due to incomplete valve closure.
• Acute MR: 🚨 Sudden, no time for LA adaptation → pulmonary oedema + acute HF.
• Chronic MR: 🕰️ Gradual; LA dilates & compensates → later LV failure.

🧬 Pathophysiology

• Volume overload: Regurgitant jet ↑ LA pressure & volume → LA dilatation, eccentric LV hypertrophy.
• Acute MR: Sudden rise in LA pressure → pulmonary oedema, cardiogenic shock.
• Chronic MR: Initially well-tolerated → progressive LV dysfunction, HF, AF.

🔎 Causes

• 🎈 Mitral Valve Prolapse (MVP): Most common in developed world.
• 🌍 Rheumatic Heart Disease: Post-strep scarring & fusion (still common globally).
• ❤️ Ischaemic Heart Disease: Papillary muscle rupture or dysfunction post-MI.
• 🦠 Infective Endocarditis: Leaflet/chordal destruction → acute/chronic MR.
• ⚙️ Degenerative Valve Disease: Annular dilatation, calcification.
• 💔 Cardiomyopathy: Dilated/HCM distorts valve apparatus.
• 👶 Congenital: Cleft/parachute valve anomalies.
• 🧬 Connective Tissue: Marfan, Ehlers-Danlos, OI.
• 🩸 Trauma: Papillary/chordal rupture after chest injury.

🩺 Clinical Features

• Symptoms: Palpitations (AF), exertional dyspnoea, fatigue, orthopnoea/PND if severe.
• Signs:
  • 🎶 Pansystolic murmur @ apex → axilla.
  • 💓 S3 gallop (volume overload).
  • Diffuse, displaced apex beat (LV dilatation).
  • Soft S1, loud P2 (pulmonary HTN).
  • ± Mid-diastolic rumble if large regurgitant volume.

🧪 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.

⚕️ Management

• 💊 Medical: – Diuretics → relieve pulmonary congestion. – ACEi/ARB → reduce afterload. – Rate control in AF (β-blockers, digoxin, Ca²⁺ blockers). – Anticoagulation in AF (per CHA₂DS₂-VASc).
• 🔧 Surgical: – Valve repair preferred (better survival, LV preservation). – Valve replacement if not repairable (mechanical vs bioprosthetic).
• 🩹 Percutaneous: – MitraClip for high-risk surgical patients. – TMVR emerging option.
• ⚡ AF Management: – Rate control, rhythm control, anticoagulation.
• 📊 Monitoring: – Serial echo (LV function, LA size, pulmonary HTN). – Clinical: symptoms, functional class.
• 🌱 Lifestyle: – Moderate exercise. – Low-salt diet. – Stop smoking, manage HTN, lipids.

📚 Teaching Pearl

💡 Think MR = pansystolic apex murmur → axilla. 🧠 Acute MR = pulmonary oedema & shock. 🕰️ Chronic MR = AF + heart failure later. Repair > Replace whenever feasible.