Skip to main content

Health condition

Mitral valve stenosis, from a rheumatic murmur to a clear treatment plan.

A narrowed mitral valve restricts blood flow into the left ventricle - most often a legacy of rheumatic fever. Echocardiography confirms it, and treatment ranges from medical management to balloon valvuloplasty or surgery. This page mirrors our detailed guide at /conditions/mitral-stenosis/.

Jump to treatment

Looking for the fuller clinical write-up? Read our companion guide: Mitral stenosis - full guide →

A radiographer guides a patient onto the bed of an advanced 3 Tesla MRI scanner in a London imaging suite

Why trust this guide

  • 01

    Editorial team

    Written by our editorial team from the UK sources listed on each page.

  • 02

    Sourced from guidance

    Checked against ESC/EACTS and AHA/ACC valve disease guidelines you can see at the end.

  • 03

    Current for 2026

    Reflects modern practice including balloon valvuloplasty selection criteria and rheumatic prophylaxis.

Key facts

Mitral valve stenosis at a glance.

The essentials, in plain English - what it is, why it happens, and how it's assessed and treated in the UK today.

  • What it is

    Narrowing of the mitral valve orifice, obstructing blood flow from the left atrium into the left ventricle.

  • Also known as

    Mitral stenosis - this page covers the same condition. See our companion guide at /conditions/mitral-stenosis/.

  • Leading cause

    Rheumatic heart disease - a late sequela of rheumatic fever, often decades after the initial infection.

  • Gold-standard test

    Transthoracic echocardiography measures valve area, gradient and pulmonary pressures - see /treatments/echocardiogram/.

  • Common complication

    Atrial fibrillation from left atrial stretch - see /conditions/atrial-fibrillation/ - raising stroke risk.

  • Definitive options

    Percutaneous balloon valvuloplasty for suitable anatomy, or surgical repair or replacement when it is not.

Why this guide matters

A rheumatic legacy, still common today.

Mitral valve stenosis often develops silently for years before symptoms appear. The three points below shape everything else on this page.

  • Rheumatic fever is the usual cause

    Most cases trace back to rheumatic fever in childhood or adolescence, with valve damage only becoming apparent decades later.

  • Echocardiography confirms everything

    A single, non-invasive scan measures valve area, gradient and pulmonary pressure - the basis for every treatment decision.

  • Intervention timing matters

    Balloon valvuloplasty or surgery works best before irreversible pulmonary hypertension or right heart failure sets in.

How the diagnosis is made

From a murmur to a confirmed valve area.

The steps a UK GP or cardiologist will normally follow, per ESC/BSE assessment pathways - so you know what to expect and why.

  1. 01

    Assessing

    History and auscultation

    A low-pitched mid-diastolic murmur with an opening snap, best heard at the apex in the left lateral position.

  2. 02

    Assessing

    Symptom and functional review

    Exertional breathlessness, fatigue and palpitations are graded against NYHA class to guide urgency.

  3. 03

    Assessing

    ECG

    Look for P-mitrale (broad, notched P waves) from left atrial enlargement, or atrial fibrillation.

  4. 04

    Confirming

    Chest X-ray

    Left atrial enlargement, straightening of the left heart border and, in advanced disease, pulmonary congestion.

  5. 05

    Confirming

    Transthoracic echocardiography

    The gold-standard test - measures valve area, mean gradient, valve morphology and pulmonary artery pressure per ESC/BSE protocol.

  6. 06

    Confirming

    Exercise testing

    Used when symptoms and resting echo findings do not match, to unmask exertional pulmonary hypertension.

  7. 07

    Preparing

    Cardiac catheterisation - selective

    Reserved for discordant non-invasive findings or before intervention when echo is inconclusive.

Typical timeline: a first echocardiogram to a settled monitoring or intervention plan within weeks.

Symptoms

What mitral valve stenosis actually feels like.

Progressive breathlessness and fatigue dominate early on, with palpitations, haemoptysis and the classic murmur along the way. And the features that mean it's time to escalate.

  • Progressive exertional dyspnoea

    The dominant symptom - breathlessness on exertion that worsens gradually as the valve narrows further.

  • Fatigue

    Reduced cardiac output from the obstructed valve limits exercise tolerance well before rest symptoms appear.

  • Palpitations

    Often the first sign of atrial fibrillation developing from a stretched, pressure-loaded left atrium.

  • Haemoptysis

    Elevated left atrial and pulmonary venous pressure can rupture small bronchial veins, producing blood-streaked sputum.

  • Mid-diastolic murmur

    A low-pitched rumble at the apex, classically with an opening snap - the hallmark auscultation finding.

  • Peripheral oedema

    A late sign reflecting right heart strain once pulmonary pressures have been elevated for some time.

  • Infective endocarditis risk

    A diseased valve is more susceptible to infection - dental and procedural precautions may be discussed.

  • Red flag - acute decompensation

    Sudden severe breathlessness, new fast atrial fibrillation or pulmonary oedema needs emergency assessment.

Palpitations from atrial fibrillation are common in mitral valve stenosis - read more in our guide to atrial fibrillation. Not every murmur means valve disease - see our overview of heart murmurs for context.

Treatment

How mitral valve stenosis is treated in the UK.

Medical management controls symptoms and stroke risk - balloon valvuloplasty or surgery address the narrowed valve itself, per ESC/AHA guidance.

  • Rate control

    Beta-blockers or rate-limiting calcium-channel blockers slow the heart, allowing more time for diastolic filling through the narrowed valve.

  • Diuretics

    Reduce pulmonary and systemic congestion by lowering circulating volume - symptomatic relief rather than a fix for the underlying obstruction.

  • Anticoagulation for AF

    Mitral stenosis with atrial fibrillation carries a high stroke risk - anticoagulation is recommended regardless of CHA2DS2-VASc score.

  • Percutaneous balloon valvuloplasty

    The preferred intervention for suitable pliable, non-calcified valves without significant regurgitation or left atrial thrombus.

  • Surgical mitral valve repair

    Considered when anatomy is unsuitable for balloon valvuloplasty but the valve can still be conserved.

  • Surgical mitral valve replacement

    Reserved for heavily calcified, distorted valves or when repair and balloon valvuloplasty are not feasible.

  • Rheumatic fever prophylaxis

    Long-term secondary antibiotic prophylaxis reduces further rheumatic valve damage in those with a rheumatic aetiology.

  • Serial echocardiographic monitoring

    Regular echo follow-up tracks valve area and gradient progression, timing intervention before irreversible complications develop.

Diagnostic imaging

Every treatment decision starts with imaging.

Echocardiography remains the primary test - see our echocardiogram guide. Cardiac MRI is sometimes used to clarify valve anatomy and ventricular function - see our cardiac MRI guide for what to expect.

What this guide is based on

The sources behind every claim on this page.

European and American cardiology society guidance, current at the time of last review.

Key references

Guidelines and standards we relied on.

A quiet reminder

This guide is for information, not medical advice.

Your GP or cardiologist knows your heart and history and can tell you which parts apply to you. If in doubt, get seen. For a more detailed clinical write-up, see /conditions/mitral-stenosis/.

  • ESC/EACTS Guidelines for the management of valvular heart disease.

  • AHA/ACC Guideline for the Management of Patients With Valvular Heart Disease.

  • British Society of Echocardiography (BSE). Guidelines on valve assessment.

  • European Society of Cardiology. Guidance on cardiac disease in pregnancy.

Red flags

When mitral valve stenosis needs urgent attention.

Most stable mitral valve stenosis is monitored in outpatient cardiology. These are the situations that aren't - and where urgent or emergency care is needed.

  • Acute pulmonary oedema

    Sudden severe breathlessness with frothy sputum signals decompensated stenosis - needs emergency hospital care.

  • New fast atrial fibrillation

    Rapid AF shortens diastolic filling time through an already narrow valve and can precipitate acute decompensation.

  • Systemic embolism

    Stroke or limb ischaemia can arise from left atrial thrombus, particularly with coexisting atrial fibrillation.

  • Haemoptysis - significant

    Heavier bleeding beyond streaking warrants urgent cardiology assessment to check for pulmonary venous hypertension.

  • Pregnancy with moderate-to-severe stenosis

    Pregnancy increases cardiac output and heart rate, which can unmask or worsen symptoms - needs specialist joint cardio-obstetric care.

  • Infective endocarditis features

    New fever, night sweats or a changing murmur in someone with valve disease needs urgent investigation.

  • Left atrial thrombus on echo

    Found before planned balloon valvuloplasty, this defers the procedure and mandates anticoagulation first.

  • Signs of right heart failure

    Ankle swelling, raised jugular venous pressure or ascites suggest longstanding pulmonary hypertension from untreated stenosis.

  • Recurrent rheumatic fever

    Further episodes accelerate valve damage - secondary prophylaxis adherence should be reviewed urgently.

Living with it

A manageable condition, with careful monitoring.

Four things that make the biggest difference day to day - keeping up with echo review, watching for rhythm changes, endocarditis precautions and pregnancy planning.

A quiet reminder

Regular review catches change early.

Mitral valve stenosis usually progresses slowly - consistent follow-up means intervention happens at the right time, not too late.

  1. 01 Monitor

    Keep echo appointments

    Serial echocardiography tracks how quickly the valve is narrowing, so intervention is timed rather than delayed.

  2. 02 Rhythm

    Watch for palpitations

    New or worsening palpitations can mean atrial fibrillation has developed - report them promptly rather than waiting for review.

  3. 03 Protect

    Discuss endocarditis precautions

    Ask your cardiology team whether antibiotic cover is needed before dental or invasive procedures.

  4. 04 Plan

    Flag pregnancy plans early

    Moderate-to-severe mitral stenosis needs pre-pregnancy counselling and specialist joint care throughout.

Frequently asked

Everything we get asked about mitral valve stenosis.

Quick answers on causes, diagnosis, balloon valvuloplasty and pregnancy.

  • What is mitral valve stenosis?

    Mitral valve stenosis is narrowing of the mitral valve orifice, which obstructs blood flow from the left atrium into the left ventricle. It is the same condition as mitral stenosis - see our full guide at /conditions/mitral-stenosis/ for further detail.

  • What causes mitral valve stenosis?

    Rheumatic heart disease, a late complication of rheumatic fever, is by far the most common cause worldwide. Less commonly it results from mitral annular calcification, congenital valve anomalies, or other rare inflammatory conditions.

  • What are the main symptoms?

    Progressive exertional breathlessness and fatigue are the earliest and most common symptoms. Palpitations from atrial fibrillation, haemoptysis and, later, signs of right heart strain can follow as the valve narrows further.

  • How is mitral valve stenosis diagnosed?

    A mid-diastolic murmur with an opening snap on auscultation raises suspicion. Transthoracic echocardiography is the gold-standard test, measuring valve area and pressure gradient, supported by ECG, chest X-ray and, occasionally, exercise testing or cardiac catheterisation.

  • What is balloon mitral valvuloplasty?

    It is a catheter-based procedure that stretches open a narrowed mitral valve using a balloon, avoiding open surgery. It works best in pliable, non-calcified valves without significant regurgitation or left atrial thrombus, following ESC/AHA suitability criteria.

  • Is mitral valve stenosis dangerous in pregnancy?

    It can be - pregnancy increases heart rate and cardiac output, which places extra strain on an already obstructed valve. Moderate-to-severe stenosis needs specialist pre-pregnancy counselling and joint cardio-obstetric management throughout.

Related content

Keep reading.