Mitral valve prolapse !

One or both mitral valve leaflets bulge back into the left atrium as the heart pumps. Usually harmless, it can cause a leak.

Updated 2026-11-01

Structures involved

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In the clinical exam

Why it happens

What it is

Mitral valve prolapse (MVP) is the systolic displacement of one or both mitral leaflets more than 2 mm above the plane of the mitral annulus into the left atrium. It is usually caused by myxomatous degeneration of the leaflets and chordae. Most people have no symptoms, but some develop progressive mitral regurgitation.

Who gets it

Affects about 2–3% of the general population and is the most common cause of primary mitral regurgitation needing surgery in high-income countries. It is seen in both sexes; severe regurgitation is more common in older men.

Causes

Primary (myxomatous) degeneration, sometimes familial
Fibroelastic deficiency in older adults (thin leaflets, chordal rupture)
Connective tissue disorders: Marfan syndrome, Ehlers-Danlos syndrome, osteogenesis imperfecta
Association with adult polycystic kidney disease

Risk factors

Family history of MVP
Connective tissue disorders
Thin body habitus, pectus excavatum and straight back syndrome (associations)

Pathophysiology

Myxomatous change thickens and lengthens the leaflets and chordae tendineae. During systole the redundant leaflets billow into the left atrium, and if coaptation fails mitral regurgitation results. Anything that reduces left ventricular volume (standing, Valsalva) makes the prolapse occur earlier; increasing volume (squatting) delays it. Chordal rupture can cause sudden severe regurgitation (flail leaflet).

Classification

Classic (leaflet thickness at least 5 mm) versus non-classic MVP
With or without mitral regurgitation (mild, moderate, severe)
Barlow disease (diffuse myxomatous excess tissue) versus fibroelastic deficiency

Symptoms and signs

Usually none; often found on examination or echocardiography
Palpitations from premature beats or arrhythmias
Atypical chest pain, fatigue or anxiety (not clearly caused by MVP)
Dyspnoea and reduced exercise tolerance when significant regurgitation develops
Auscultation: mid-systolic click, often followed by a late systolic murmur at the apex

Diagnosis

Clinical: A mid-systolic click with or without a late systolic murmur at the apex. With Valsalva or standing the click comes earlier and the murmur lengthens; with squatting or handgrip the click moves later.
Tests: ECG is often normal; it may show premature beats or non-specific ST-T changes. Ambulatory ECG for palpitations or syncope.
Imaging: Transthoracic echocardiography is the diagnostic test: it confirms prolapse, measures leaflet thickness and grades regurgitation and left ventricular size and function. Transoesophageal echocardiography to plan repair; cardiac MRI for ventricular fibrosis in selected patients.

Differential diagnosis

Other causes of mitral regurgitation (rheumatic, ischaemic, functional)
Hypertrophic cardiomyopathy (murmur also increases with Valsalva)
Tricuspid valve prolapse
Anxiety or panic disorder as a cause of palpitations and chest pain

Goal of treatment

Reassure patients with uncomplicated prolapse, follow regurgitation over time, and repair the valve before irreversible left ventricular damage.

Treatment

Lifestyle: Reassurance and education for most patients; normal activity is usually allowed; reducing caffeine and stimulants may help palpitations.
Medical: Beta-blockers for symptomatic palpitations; heart failure therapy and anticoagulation when atrial fibrillation or heart failure develops.
Surgical: Mitral valve repair (preferred over replacement) for severe symptomatic regurgitation or asymptomatic severe regurgitation with left ventricular dysfunction or dilation, new atrial fibrillation or pulmonary hypertension.
Procedure: Transcatheter edge-to-edge repair for patients with severe regurgitation at high surgical risk.
Follow-up: Periodic echocardiography depending on regurgitation severity; good dental hygiene. Routine endocarditis prophylaxis is not recommended for MVP alone.

Complications

Progressive mitral regurgitation and heart failure
Chordal rupture with acute severe regurgitation
Atrial fibrillation
Infective endocarditis
Ventricular arrhythmias and rare sudden death («arrhythmic MVP»)

Prognosis

Excellent for most people, with a normal life expectancy. Risk rises with thick leaflets, moderate or severe regurgitation, reduced ventricular function and older age. Early valve repair restores near-normal survival.

Prevention

No way to prevent primary MVP
Regular follow-up to detect worsening regurgitation early
Good oral hygiene to reduce endocarditis risk

Test yourself

Think of the answer, then tap the question to see it.

What is the classic auscultatory finding in MVP?

A mid-systolic click, often followed by a late systolic murmur at the apex.

What happens to the click with Valsalva or standing?

It occurs earlier and the murmur becomes longer, because left ventricular volume falls.

Which pathological change underlies most MVP?

Myxomatous degeneration of the leaflets and chordae tendineae.

Which connective tissue disorder is classically associated with MVP?

Marfan syndrome (also Ehlers-Danlos).

What is the preferred surgical treatment for severe regurgitation from MVP?

Mitral valve repair.

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Educational information, not medical advice. For any symptom, see a health professional.

Sources: Mitral valve prolapse (MedlinePlus, US National Library of Medicine, 2026).

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Representative model, for educational purposes only.

Mitral anterior leaflet highlighted on the Durgical 3D model