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Cardiovascular

Mitral Regurgitation

Mitral regurgitation is systolic leakage from the LV into the LA; chronic disease causes volume overload, while acute severe disease can cause pulmonary oedema.

In a nutshell

Mitral regurgitation is systolic backflow. Distinguish acute from chronic and primary from secondary disease, quantify it with integrated echo, optimise secondary MR, and refer severe symptomatic or LV-decompensating disease.

Classic presentation

Exertional breathlessness with a pansystolic apical murmur radiating to the axilla, often with LA enlargement or AF.

Key points

  • A pansystolic murmur supports MR but echo defines severity and mechanism.
  • Acute severe MR can cause pulmonary oedema or shock even when the murmur is not loud.
  • Primary MR is a valve problem; secondary MR reflects LV/LA remodelling and needs HF optimisation first.
  • Offer intervention for symptomatic severe MR.
  • In asymptomatic severe primary MR, consider intervention before LV dysfunction using NICE EF and ESD triggers.
  • Repair is preferred when durable repair is suitable; selected inoperable patients with severe secondary MR may be considered for transcatheter edge-to-edge repair.

First-line investigation

TTE with integrated severity, mechanism, LV/LA and pulmonary-pressure assessment.

Management

Recognise acute MR

  • Pulmonary oedema, shock or a new murmur after infarction, endocarditis or chordal/papillary injury requires emergency valve-team care.1,2

Define mechanism and severity

  • Use TTE, escalating to TOE or 3D imaging when anatomy, endocarditis or intervention planning requires it.1,2

Refer severe primary MR

  • Offer intervention for symptomatic severe MR; consider asymptomatic severe primary MR at the NICE LV, dimension, AF or pulmonary-pressure triggers.1

Optimise secondary MR

  • Optimise HF therapy and address rhythm/ischaemic disease before considering intervention for persistent severe secondary MR.1

Monitor ventricular and rhythm response

  • Trend symptoms, LV/LA size, EF, pulmonary pressure and AF; new deterioration should trigger earlier review.1,2

Exam traps

  • An eccentric MR jet can appear deceptively small; integrate multiple measures.
  • Preserved EF can conceal early LV dysfunction in severe MR.
  • Do not apply the primary-MR pathway to secondary MR without HF optimisation and mechanism assessment.
  • New AF or pulmonary hypertension can trigger earlier review even if symptoms are limited.

Illustrations

Severe eccentric mitral regurgitation on echocardiographyTransoesophageal echocardiography showing a large eccentric systolic colour-Doppler jet through the mitral valve, with complementary 3D valve views.Kumi DD et al., JACC. Case reports 2026, CC-BY-4.0 · CC-BY-4.0

Key sources

  1. NICE NG208: Heart valve disease presenting in adults (Referral, investigation, pharmacological management, intervention and follow-up recommendations)Published 17 Nov 2021 | Updated 24 Oct 2025
  2. British Society of Echocardiography: Echocardiographic assessment of the mitral valve (UK assessment guideline for mitral stenosis and regurgitation)Published 1 Sept 2021
  3. NICE NG196: Atrial fibrillation: diagnosis and management (Anticoagulation recommendations and scope)Published 27 Apr 2021 | Updated 19 Jun 2024
  4. NICE NG208: Heart valve disease presenting in adults — overview (Current guideline status and update information)Published 17 Nov 2021 | Updated 24 Oct 2025
  5. BSE/BHVS: Clinical indications and triage for echocardiography in heart valve disease (UK consensus on referral, red flags and surveillance)Published 1 Aug 2024

This page is exam revision material, not medical advice, and must not be used for patient care. Always check drug doses against the BNF and current guidance. Full disclaimer.