Makindo Medical Notes

Related Subjects: | Mitral Regurgitation (Incompetence) | Mitral Stenosis | Mitral Stenosis vs Regurgitation | Mitral Valve Prolapse | Atrial Fibrillation (AF) | Cardiac Valve Replacement | Prosthetic Valves

📖 About Mitral Valve Disease

• Mitral stenosis (MS) is most commonly secondary to rheumatic fever 🌍.
• Symptoms usually appear once valve area 2 cm² (normal 4–6 cm²).
• Severe disease (<1 cm²) is surgically treatable ✅.

🧬 Aetiology

• 🔹 Rheumatic Heart Disease (RHD): Scarring → classic "fish-mouth" valve.
• 🔹 Congenital MS: Often with other cardiac anomalies.
• 🔹 Mitral Annular Calcification: Elderly, CKD patients.
• 🔹 Rare: Radiation, infective endocarditis, SLE, carcinoid syndrome.

🩺 Clinical Features

• ❤️ Cardiac: AF with irregular low-volume pulse; loud S1; tapping apex; mid-diastolic murmur with presystolic accentuation.
• 🌬️ Pulmonary: Pulmonary oedema (from ↑ LA pressure), dyspnoea, orthopnoea, P2 loud, RV lift (pulmonary hypertension).
• 🧠 Systemic / Complications: Embolic events, Ortner’s syndrome (hoarseness from LA enlargement), dysphagia, bronchiectasis (compression).

⚠️ A shorter interval between S2 and the opening snap = higher LA pressure → severe MS.

📉 Decompensation Triggers

• Exercise, stress, infection, pregnancy 🤰.
• Uncontrolled AF → acute pulmonary oedema.

🔍 Differential Diagnosis

• Left atrial myxoma → mimics MS with "tumour plop".

🧪 Investigations

• ECG: AF, P mitrale, RBBB, RVH.
• CXR: LA enlargement, pulmonary oedema, straightened left heart border.
• Echo (gold standard): Shows valve thickening, fusion, ↓ mobility. TEE most accurate.
• Cardiac catheterisation: Confirms pressure gradients (LA vs LV).
• Bloods: FBC, U&E, LFT, CRP (exclude secondary causes).

📏 Severity by Valve Area

• ✅ Normal: 4–6 cm²
• 🟢 Mild: 1.5–2.5 cm²
• 🟡 Moderate: 1–1.5 cm²
• 🔴 Severe: <1 cm²

💊 Management

• Medical: - Diuretics for congestion 💦 - Rate control (β-blockers, CCBs, digoxin) in AF - Anticoagulation: Warfarin is mandatory in MS with AF (DOACs contraindicated 🚫)
• Intervention: - Percutaneous Mitral Balloon Valvotomy (PMBV) = 1st line if favourable valve anatomy. - Surgery (repair or replacement) if unsuitable for PMBV or severe calcification.
• AF management: Rate control ± rhythm control; anticoagulation essential.
• Lifestyle: Salt restriction, avoid strenuous activity, regular follow-up echos.
• Pregnancy: MS often decompensates in 2nd trimester; manage AF, avoid anticoagulation risks with DOACs, consider heparin/warfarin strategy.

🩺 Case 1 — Young Woman with Rheumatic Heart Disease

A 28-year-old woman from South Asia presents with progressive exertional breathlessness and orthopnoea. She reports palpitations. On exam: malar flush, tapping apex beat, loud first heart sound, and an opening snap with a mid-diastolic murmur at the apex. Echo confirms moderate mitral stenosis. Management: 🩺 Rate control (beta-blocker) for palpitations/AF risk, anticoagulation if AF develops, diuretics for congestion. Consider percutaneous balloon valvotomy if symptomatic with suitable valve morphology. Avoid: ❌ Pregnancy without preconception counselling in severe MS (risk of decompensation); avoid tachycardia (shortens diastole and worsens filling).

🩺 Case 2 — Elderly Patient with Complications

A 70-year-old man presents with worsening dyspnoea, ankle swelling, and haemoptysis. Exam: irregularly irregular pulse, loud S1, and mid-diastolic murmur at apex. Echo shows severe calcific mitral stenosis with left atrial enlargement and pulmonary hypertension. Management: 🚑 Long-term anticoagulation for AF, diuretics for fluid overload, referral for surgical valve replacement (balloon valvotomy less effective in heavily calcified valves). Oxygen and pulmonary vasodilators may be considered if severe pulmonary hypertension. Avoid: ❌ Delaying surgical referral; avoid verapamil/diltiazem in decompensated HF; avoid strenuous exertion.