---
title: Mitral valve prolapse
description: What mitral valve prolapse is, why it happens, how it is found, when it needs treatment and which complications need urgent help.
type: disease
aliases:
  - MVP
  - Barlow disease
sources:
  - tier: guideline
    org: minzdrav-rf
    title: Митральная недостаточность
    year: 2024
    url: https://cr.minzdrav.gov.ru/view-cr/881_1
  - tier: guideline
    org: esc
    title: 2025 ESC/EACTS Guidelines for the management of valvular heart disease
    year: 2025
    doi: 10.1093/eurheartj/ehaf194
    url: https://doi.org/10.1093/eurheartj/ehaf194
  - tier: guideline
    org: minzdrav-rf
    title: Врожденная митральная недостаточность
    year: 2025
    url: https://cr.minzdrav.gov.ru/view-cr/744_2
  - tier: guideline
    org: nice
    title: 'Prophylaxis against infective endocarditis: antimicrobial prophylaxis against infective endocarditis in adults and children undergoing interventional procedures (CG64)'
    year: 2016
    url: https://www.nice.org.uk/guidance/cg64
  - tier: reference
    org: msd-manuals
    title: Mitral Valve Prolapse (MVP) (MSD Manual Professional Version)
    year: 2025
    url: https://www.msdmanuals.com/professional/cardiovascular-disorders/valvular-disorders/mitral-valve-prolapse-mvp
  - tier: reference
    org: msd-manuals
    title: Mitral Valve Prolapse (MVP) (MSD Manual Consumer Version)
    year: 2025
    url: https://www.msdmanuals.com/home/heart-and-blood-vessel-disorders/heart-valve-disorders/mitral-valve-prolapse-mvp
  - tier: reference
    org: msd-manuals
    title: Cardiac Auscultation
    year: 2025
    url: https://www.msdmanuals.com/professional/cardiovascular-disorders/approach-to-the-cardiac-patient/cardiac-auscultation
sources_checked: 2026-10-13
review: null
---

Mitral valve prolapse (MVP) is when the leaflets of the <Structure id="mitral-valve">mitral valve</Structure> bulge back into the <Structure id="left-atrium">left atrium</Structure> while the <Structure id="left-ventricle">left ventricle</Structure> contracts (systole).<Cite n={[5, 6]} /> MVP is common: about 2.4% of people have it.<Cite n={[1, 5]} /> Most people with MVP have no symptoms, and it is usually benign.<Cite n={[5, 6]} /> The main complication is [mitral regurgitation](../mitral-regurgitation/), when the valve lets blood leak back into the atrium: MVP is the main cause of primary chronic mitral regurgitation.<Cite n={[1, 5]} />

<Diagram name="mitral-valve-prolapse">
  <p slot="normal">
    The diagram shows the left side of the heart, cut lengthwise, at the moment the left ventricle
    contracts. The mitral valve sits between the left atrium and the left ventricle: it opens to let
    blood into the ventricle and closes as the ventricle contracts to pump blood into the
    aorta.<Cite n={6} /> Beneath the valve are thin cords (chordae) and papillary muscles.<Cite n={5} />
    Doctors judge how the edge of the leaflets moves relative to the plane of the valve annulus; the
    annulus is drawn as a dashed line.<Cite n={3} />
  </p>
  <p slot="disease">
    In prolapse the leaflets are most often changed by myxomatous degeneration: they are larger and
    softer than usual, the chordae are longer and thinner, and when the ventricle contracts a leaflet
    bulges into the left atrium.<Cite n={5} /> The diagram shows the posterior leaflet bulging, as in
    the echocardiography image in MSD.<Cite n={5} /> With prolapse, blood sometimes leaks back into
    the atrium, so the jet is drawn as a thin dashed line.<Cite n={6} />
  </p>
</Diagram>

## Why it happens

<Patient>

The most common cause is myxomatous degeneration of the valve. The layer of collagen fibres in the leaflets thins and loose (mucoid) material builds up in them; the chordae become longer and thinner, and the leaflets enlarge and become stretchy. These floppy leaflets bulge back into the atrium when the ventricle contracts.<Cite n={5} />

Usually the cause of these changes is unknown, but they can run in families.<Cite n={5} /> MVP is more common in inherited connective tissue disorders, for example [Marfan syndrome](../marfan-syndrome/), Ehlers-Danlos syndrome and osteogenesis imperfecta.<Cite n={[3, 5]} /> MVP usually appears after the growth spurt of adolescence.<Cite n={5} />

</Patient>

<Student>

In the Carpentier functional classification of mitral regurgitation, leaflet prolapse is type II, which also includes chordal elongation, rupture or absence and papillary muscle elongation; the type of dysfunction is defined by how the free edge of the leaflet moves relative to the annular plane.<Cite n={[1, 3]} /> MVP has its own ICD-10 code, I34.1.<Cite n={1} /> Mitral regurgitation at a young age is typical of myxomatous MVP (Barlow disease); in these patients a heart murmur may be heard from childhood.<Cite n={1} />

According to MSD, the 2.4% prevalence depends on the echocardiographic criteria used.<Cite n={5} /> The Russian Ministry of Health guideline for children says prolapse is found more often in patients with an asthenic build, congenital chest wall deformities and a thin anterior chest wall.<Cite n={3} /> According to MSD, pectus excavatum, hypokyphosis and a narrow anteroposterior chest diameter are associated with MVP but are not diagnostic of it.<Cite n={5} />

</Student>

<HeartModel highlight={['mitral-valve']} />

## Symptoms

<Patient>

Most people with MVP have no symptoms.<Cite n={[5, 6]} /> Some have chest pain, palpitations, shortness of breath, dizziness, migraines or tiredness; these symptoms are hard to explain by the way the valve works alone.<Cite n={[5, 6]} /> In some people palpitations come on with emotional stress; they may be caused by harmless rhythm disturbances, for example extra heartbeats (premature beats).<Cite n={5} />

MVP causes serious heart problems if the regurgitation becomes severe, the valve becomes infected ([infective endocarditis](../infective-endocarditis/)) or weakened tissue, such as a chord, ruptures.<Cite n={[5, 6]} />

</Patient>

<Student>

MVP without regurgitation often causes a crisp mid-systolic click as the subvalvular apparatus abruptly tightens; with regurgitation the click is followed by a late systolic murmur.<Cite n={5} /> The Russian Ministry of Health guideline calls the mid-systolic click with a late systolic murmur the pathognomonic auscultatory sign of MVP.<Cite n={1} /> The click is heard best with the diaphragm of the stethoscope over the apex with the patient in the left lateral decubitus position.<Cite n={5} /> Manoeuvres that decrease LV size (sitting, standing, the Valsalva manoeuvre) move the click closer to S1 and make the murmur appear or become louder and longer; squatting or isometric handgrip delays the click and shortens the murmur.<Cite n={[1, 5]} />

According to MSD, the sequelae of MVP with regurgitation are [heart failure](../heart-failure/), infective endocarditis and [atrial fibrillation](../atrial-fibrillation/) with thromboembolism; whether MVP causes stroke or endocarditis independent of regurgitation and atrial fibrillation is unclear.<Cite n={5} /> Ventricular ectopy is common in MVP, while severe [ventricular arrhythmias](../ventricular-tachycardia/) are rare and associated with sudden cardiac death.<Cite n={5} /> They are associated with severe myxomatous change of the leaflets, severe regurgitation, myocardial fibrosis and mitral annular disjunction (MAD), a partial detachment of the annulus from the ventricular myocardium during systole.<Cite n={5} /> Sudden death in MVP is rare; it occurs most often with ruptured or otherwise abnormal chordae and/or flail leaflets.<Cite n={5} />

</Student>

## How it is diagnosed

<Patient>

A doctor may suspect MVP on hearing the typical click, or a murmur suggesting mitral regurgitation, when listening to the heart.<Cite n={6} /> The diagnosis is confirmed with a heart ultrasound ([echocardiography](../../diagnostic/echocardiography/)): it shows the bulging leaflets and, if the valve leaks, how severe the leak is.<Cite n={[5, 6]} /> The shape of the chest alone does not make the diagnosis.<Cite n={5} />

If a person has mitral regurgitation, the Russian Ministry of Health guideline advises lifelong follow-up with a cardiologist, and seeing a doctor straight away if symptoms change.<Cite n={1} />

</Patient>

<Student>

The Russian Ministry of Health guideline recommends transthoracic echocardiography for all patients with mitral regurgitation or suspected regurgitation, and during follow-up, to identify the mechanism and severity of regurgitation.<Cite n={1} /> According to MSD, thickened, redundant leaflets indicate more extensive myxomatous degeneration and a greater risk of endocarditis and regurgitation.<Cite n={5} /> The click of MVP may be confused with the click of congenital aortic stenosis, but the latter occurs very early in systole and does not move with changes in posture.<Cite n={5} />

Mitral annular disjunction is diagnosed on echocardiography from systolic separation of the annulus and the ventricular myocardium in the posterolateral region.<Cite n={5} /> MSD links it to an increased risk of sudden arrhythmic death and recommends ambulatory heart rhythm monitoring (see [Holter monitoring](../../diagnostic/holter-monitoring/)); this is the position of the MSD reference.<Cite n={5} />

</Student>

<HeartSounds sound="mitral-valve-prolapse" />

## How it is treated

<Patient>

MVP usually needs no treatment.<Cite n={[5, 6]} /> If palpitations are troublesome, a doctor may prescribe medicines that ease the symptoms, but there is no evidence that they improve the outlook.<Cite n={5} /> If atrial fibrillation develops, it is treated.<Cite n={5} />

If the valve starts to leak, treatment depends on how severe the regurgitation is and how the atrium and ventricle have changed; more in the article on [mitral regurgitation](../mitral-regurgitation/).<Cite n={5} /> With severe regurgitation, if surgery is needed, the valve is repaired rather than replaced whenever possible; when and how to operate is decided by a team of specialists.<Cite n={[1, 2]} />

Whether antibiotics are needed before dental treatment and other procedures is up to the doctor: guidelines differ on this.<Cite n={[1, 4, 5]} /> NICE advises health professionals to explain to people with valve disease in which the valve leaks why good oral health matters and which symptoms may point to endocarditis.<Cite n={4} />

</Patient>

<Student>

Indications for surgery in severe primary regurgitation and the choice between repair, replacement and transcatheter edge-to-edge repair (TEER) are covered in the article on [mitral regurgitation](../mitral-regurgitation/). In prolapse the anatomy of the lesion matters: according to the Russian Ministry of Health guideline, the most favourable lesion for repair is prolapse of the posterior leaflet of non-rheumatic origin, while involvement of the anterior leaflet or both leaflets makes repair less likely.<Cite n={1} />

ESC lists complex repair (Barlow disease, anterior or bileaflet prolapse) among the procedures ideally performed in the most experienced Heart Valve Centres.<Cite n={2} /> According to MSD, finding MAD can change the surgical repair technique; MAD is repaired surgically, not by TEER.<Cite n={5} />

Sources differ on endocarditis prophylaxis. MSD does not recommend antibiotic prophylaxis in MVP except after valve replacement; NICE does not recommend it routinely for dental and certain other procedures; the patient appendix of the Russian mitral regurgitation guideline recommends antibiotic cover for any invasive procedure. The main text of that guideline says patients should be informed about endocarditis prevention, including skin and oral hygiene. The decision on prophylaxis is made by the doctor in each case.<Cite n={[1, 4, 5]} /> MSD recommends anticoagulants to prevent thromboembolism only for patients with atrial fibrillation or a prior transient ischaemic attack or stroke.<Cite n={5} />

</Student>

## When to call an ambulance

MVP itself is usually benign,<Cite n={[5, 6]} /> but some of its complications need urgent help. Rupture of a chord in MVP can cause acute severe regurgitation that presents as pulmonary oedema.<Cite n={[1, 5]} /> If severe shortness of breath comes on suddenly, call your local emergency number (112 in the EU, 911 in the US and Canada, 999 in the UK). The signs of acute regurgitation are described in the article on [mitral regurgitation](../mitral-regurgitation/).

Rarely, MVP first shows itself as infective endocarditis (for example with fever, weight loss or thromboembolism) or a stroke.<Cite n={5} /> At any sign of a stroke, call your local emergency number straight away. As with any heart condition, call an ambulance for fainting, chest pain or severe shortness of breath: this is the site's general safety rule, repeated at the bottom of every page.

<Quiz />