Mitral Regurgitation — SAQ

Stem

A candidate is asked to manage a classic presentation of Mitral Regurgitation in an exam setting. Use precise definitions, scores, doses, and decision thresholds.

Core knowledge (model answer backbone)

Mitral regurgitation (MR) is systolic backflow of blood from the left ventricle (LV) into the left atrium (LA) through an incompetent mitral valve. Chronic MR runs an asymptomatic compensated phase (LA and LV dilate, eccentric hypertrophy) before decompensation with dyspnoea, fatigue and atrial fibrillation. Acute MR (papillary-muscle or chordal rupture post-MI) presents as fulminant pulmonary oedema and cardiogenic shock. Cardinal sign: pansystolic murmur at the apex radiating to the axilla, soft S1, and a third heart sound. Diagnosis and grading are by echocardiography (EROA, regurgitant volume/fraction, vena contracta). Definitive treatment is mitral valve repair (preferred) or replacement; surgery timing rests on symptoms or LV dysfunction (EF under 60% or LV end-systolic diameter at least 40 mm). Transcatheter edge-to-edge repair (MitraClip) is an option for inoperable functional MR (COAPT).

Red flags

• Acute severe MR post-MI with pulmonary oedema and shock - papillary muscle or chordal rupture; emergency echo, vasodilators, IABP, urgent surgery
• Severe chronic MR with EF under 60% or LVESD at least 40 mm - refer for valve surgery even if asymptomatic to prevent irreversible LV dysfunction
• New atrial fibrillation in severe MR - anticoagulate (CHA2DS2-VASc) and reassess surgical timing
• Pansystolic murmur louder with handgrip (afterload) and softer with Valsalva - left-sided regurgitant lesion, likely MR

High-yield structure examiners expect

Cover: Overview & Definition, Classification, Causes — Acute vs Chronic, Epidemiology & Risk Factors, Pathophysiology, Clinical Presentation.

Key doses / thresholds (from topic teaching)

• regurgitant volume at least 45 mL) because the regurgitant orifice is dyn
• RV under 30 mL" },
• RV at least 60 mL, RF at least 50%, VC at least 0
• RV at least 45 mL) — dynamic orifice, failing LV
• eter at least 60 mm OR LA volume at least 60 mL/m² as supportive)
• RV under 60 mL (disproportionate MR)", finding: "TEER

Questions

a) Define the condition and give the most important classification or severity framework used in exams. (3 marks)

• Clear one-line definition matching standard teaching.
• Named classification / stages / types with discriminating features.
• One sentence on why classification changes management.

b) Outline pathophysiology in a mechanism chain that explains the main clinical features. (3 marks)

• Initiating insult → intermediate pathway → end-organ effect.
• Link at least two symptoms/signs to mechanism.
• Mention one complication pathway (e.g. shock, perforation, herniation, arrhythmia).

c) List discriminating clinical features and bedside assessment. (3 marks)

• Classic presentation plus one atypical group (elderly, pregnancy, child, immunocompromised).
• Named signs/manoeuvres if relevant.
• What must never be missed on exam/bedside (pregnancy test, airway, glucose, etc.).

d) Investigations with thresholds and one named score if applicable. (3 marks)

• First-line tests and what positive findings mean.
• Gold-standard or definitive investigation when needed.
• Score components reproduced exactly if a named score is standard for this topic.

e) Immediate resuscitation and definitive management with doses where standard. (3 marks)

• ABC / time-critical steps first.
• First-line drug(s) with agent + dose + route (or procedure steps).
• Escalation triggers (theatre, ICU, thrombolysis window, antidote, etc.).
• Disposition and safety-netting.

Marking tips

Full marks require specificity (numbers, names, doses) not generic "give antibiotics/fluids." Regional practice (ICMR / NICE / AHA) may be cited as alternative where relevant.