Mitral Valve Prolapse

Meet the patient

A 28-year-old woman is sent to you by her GP, who heard "an extra sound" at a routine examination. She is thin, mildly anxious, and has occasional palpitations and sharp, fleeting left-sided chest pain that has frightened her more than once in the middle of the night. At the apex you hear a clear mid-systolic click followed by a short late systolic murmur; when she squats, the click moves later, and when she stands, it moves earlier.^[19]

Three questions decide her care, and they are the questions that decide every MVP case: is the click-murmur really MVP, and not HOCM? (the manoeuvre response settles it), how much mitral regurgitation is hiding behind the eccentric jet? and — the one that makes MVP an exam topic at all — is this the benign common phenotype, or the rare arrhythmic one that can kill?^[19][3]

A structural finding, not a clinical syndrome — and why that matters

MVP is an echocardiographic diagnosis, not an auscultatory one. The definition is operational: abnormal systolic displacement of one or both mitral leaflets more than 2 mm beyond the mitral annular plane in the parasternal long-axis view, with leaflet thickness at least 5 mm defining the "classic" form. The click-murmur is one presentation of MVP — it is not the definition, and a prolapsing leaflet is not automatically pathological.^[1][8]

The valve abnormality is driven by myxomatous degeneration: the leaflet spongiosa is infiltrated by proteoglycans, collagen is fragmented, and the chordae elongate (and may rupture). When prolapse produces incomplete coaptation, mitral regurgitation follows — and MR is the mechanical, symptomatic, prognostic and operative determinant of MVP. The mitral annulus may dilate and may separate from the ventricular myocardium — mitral annular disjunction (MAD) — the substrate for the rare arrhythmic syndrome.^[4][3]

Two exam mistakes recur. The first is diagnosing MVP from a click alone — confirm it on echo. The second is calling a thin, anxious young person "MVP" without checking that the leaflet displacement is real and pathological, because physiological prolapse at very low body mass is rarely clinically relevant.^[1][8]

Etymology for viva gold: myxomatous comes from the Greek myxa, mucus — the degenerated leaflet looks glistening and jelly-like to the surgeon. Barlow syndrome honours John Barlow of Johannesburg, who in 1979 nailed down the "specific billowing mitral leaflet syndrome"; the older name "click-murmur syndrome" captures the bedside description that preceded the echo era.^[19]

The face-off — two morphologies that decide the operation

Before you treat, sort the morphology: focal fibroelastic deficiency, or diffuse Barlow disease? The two look alike at the stethoscope and nothing alike in the operating room.^[18]

^{[18] [19]}

The discriminator line: focal P2 with abrupt chordal rupture is fibroelastic deficiency and repairs easily; bileaflet Barlow disease is diffuse, demanding, and best sent to a high-volume mitral centre.^[18][17]

Enlarge

How common, who, and the exceptions that matter

Population prevalence is 2 to 3 percent by the modern 2 mm echo criterion; the older 5 to 15 percent figure used looser thresholds and over-diagnosed thin-leaflet billowing. In the Framingham offspring cohort, 84 of 3,491 adults (2.4 percent) had MVP — 1.3 percent classic (leaflet thickness at least 5 mm) and 1.1 percent non-classic — and their age and sex distributions were similar to those of subjects without prolapse. So the widely quoted 2:1 female predominance is a feature of referral series, not of the community; what Framingham did show is that people with MVP are leaner. Female predominance is real, however, in the sub-phenotypes: mitral annular disjunction was present in 61 percent of women versus 38 percent of men with myxomatous disease, and the arrhythmic MVP patient is usually a woman.^[1][4][22]

MVP is usually benign — say it out loud, then name the exceptions. The community natural-history data are risk-stratified, not a single number. In the Olmsted County cohort of 833 patients with asymptomatic MVP, MVP-related events reached 20 ± 2 percent at 10 years overall, but the distribution was extreme: patients with 0 or 1 secondary risk factor (slight MR, LA at least 40 mm, flail leaflet, AF, age at least 50) had MVP-related events of 0.2 percent per year and 10-year mortality of 5 ± 2 percent — no worse than expected; two or more secondary risk factors gave 1.7 percent per year; and a primary risk factor (moderate-to-severe MR, or EF under 50 percent) gave 15 percent per year with 45 ± 9 percent 10-year mortality. Estimated sudden-death risk across MVP is 0.2 to 1.9 percent per year. The clinical task is not to treat the large majority who will never have an event; it is to find the few who will.^[32][24][2]

Risk factors are younger age for the myxomatous (Barlow) form and older age for fibroelastic deficiency and chordal rupture, the connective-tissue disorders (Marfan, Ehlers-Danlos, Loeys-Dietz, osteogenesis imperfecta), familial non-syndromic MVP (FLNA, DCHS1 and DZIP1 are the identified causative genes in myxomatous forms, and they explain only a small proportion of cases), low body mass, and prior rheumatic fever or endocarditis for secondary MVP. The MASS phenotype (Mitral valve, Aorta, Skeleton, Skin) is a marfanoid syndrome that does not fulfil the Ghent criteria; its genetic background is unknown, though FBN1 variants have been found in some patients.^[30][33]

The pathology reads in five layers

MVP is a biomechanical failure of the leaflets and subvalvular apparatus, with downstream atrial, ventricular and — in a minority — arrhythmogenic remodelling. Each layer earns its place because it changes something you do.^[18]

1. Leaflet and chordal pathology — myxomatous degeneration. The spongiosa expands with proteoglycans, collagen fragments, the fibrosa thins; leaflets become redundant and thickened (over 5 mm) and prone to prolapse. Chordae elongate (allowing prolapse) and may rupture acutely (fibroelastic deficiency). The annulus dilates, accentuating non-coaptation. Strain on the leaflet accelerates degeneration — a positive-feedback loop.^[18][19]

2. Mitral annular disjunction (MAD). The systolic separation of the mitral annulus from the ventricular myocardium, visible on echo as a wide gap between the atrial wall-mitral valve junction and the top of the LV free wall. It was originally described in myxomatous mitral valve disease and then shown to be common and recognisable on plain transthoracic echo — present in 21 of 38 (55 percent) myxomatous MVP patients, mean length 7.4 mm — with paradoxical systolic enlargement of the annulus and, when MAD exceeds 8.5 mm, prediction of non-sustained VT on Holter. MAD drives abnormal annular motion and mechanical traction on the inferolateral basal myocardium — implicated in the arrhythmic phenotype.^[4][3]

3. The inferolateral basal myocardium and ventricular arrhythmia. Cardiac MRI with late gadolinium enhancement in arrhythmic MVP shows focal fibrosis of the papillary muscles and inferobasal wall, with repolarization abnormalities in the inferior leads and frequent, complex PVCs (right-ventricular-outflow, fascicular or papillary-muscle origin) on Holter. The combination of mechanical stretch from MAD, myxomatous valve disease, and basal fibrosis — substrate plus trigger — is the mechanism for polymorphic VT and VF.^[22][20]

4. MR — the haemodynamic axis. Mild MR is late systolic and eccentric; posterior leaflet prolapse directs the jet anteriorly, hugging the LA wall — easy to underestimate on colour Doppler. Severe MR drives chronic volume overload: LA enlargement, AF onset, pulmonary venous hypertension, and LV eccentric hypertrophy with a falling EF to 60 percent or less — the surgical trigger.^[8][30]

5. The autonomic axis. A subset has a dysautonomia-like phenotype — exaggerated sympathetic response, orthostatic intolerance, panic-like symptoms — that may account for palpitations and atypical chest pain independent of MR. Beta-blockade is mechanistically rational here.^[1][19]

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The bedside signature — the click that moves

The single most examined physical sign in MVP is a mid-systolic click whose timing shifts with preload. That shift is the bedside signature, and it tells MVP from HOCM in five seconds. It is not folklore: at 45 degrees head-up tilt, LV end-diastolic and end-systolic volumes both fell and mitral prolapse increased in 12 of 14 patients, with the click moving earlier and the murmur becoming longer and often louder; and reducing venous return with limb congesting cuffs moved the phonocardiographic click significantly towards S1 as the ventricular dimensions shrank.^[35][36][19]

• Mid-systolic click — high-pitched, best heard at the apex, produced by sudden tensing of the prolapsing leaflet and its chordae. Position matters for whether you hear it at all: the characteristic findings were present in 51 percent of MVP patients supine, 68 percent in the left lateral decubitus position and 76 percent upright.^[38]
• Late systolic murmur — starts after the click, crescendos to S2; the jet is eccentric (anterior) if the posterior leaflet prolapses, sometimes harsh or musical.
• The dynamic rule, the whole point: anything that shrinks the LV (Valsalva strain, standing) lets the leaflet prolapse earlier — the click moves toward S1 and the murmur lengthens. Anything that fills the LV (squatting, handgrip) delays prolapse — the click moves toward S2 and the murmur shortens.^[35][36]

MR signs appear when MR is severe — apical thrill, pan-systolic axillary radiation, a displaced apex from LV dilatation, an S3, and signs of pulmonary hypertension (loud P2, raised JVP). Auscultation alone cannot exclude MVP: 24 percent of echo-confirmed MVP patients had none of the characteristic auscultatory findings in any position, so when the patient is sent for palpitations and the praecordium is silent, the diagnosis rests on echo.^[38][8]

The arrhythmic phenotype — the exception that kills

A small subset of MVP causes sudden cardiac death in the young, and the 2022 EHRA consensus codified it as arrhythmic MVP. Recognise the triad before you reassure anyone.^[3][22]

The phenotype is bileaflet myxomatous prolapse plus mitral annular disjunction plus fibrosis of the papillary muscles and inferobasal wall, usually a woman with preserved LV function and only mild-to-moderate MR. The bedside markers are repolarization abnormalities in the inferior leads (II, III, aVF) on ECG, frequent complex PVCs arising from the papillary muscles or fascicular tissue on Holter, and late gadolinium enhancement of the inferobasal wall on cardiac MRI. Estimated sudden-death risk across MVP runs at roughly 0.2 to 1.9 percent per year — small in absolute terms, catastrophic in a young patient.^[22][24]

Investigations — echo first, then stratify by risk

Transthoracic echo is the diagnostic cornerstone, and it does four jobs at once: confirm the diagnosis, grade MR severity, measure LV and LA size and pulmonary pressures, and look for MAD. The workup then steps up only for the symptomatic or high-risk patient.^[1]

• 12-lead ECG — usually normal; inferior T-wave inversion (II, III, aVF) and biphasic lateral T-waves mark arrhythmic MVP with basal fibrosis. ST elevation as in pericarditis should not be attributed to MVP.^[22][24]
• TTE — parasternal long-axis for leaflet displacement more than 2 mm above the annulus (usually P2), leaflet thickness, annular diameter, and MAD; apical views for coaptation, billowing and MR severity by vena contracta, EROA and regurgitant volume (PISA). An eccentric, anterior, wall-hugging jet is characteristic of posterior leaflet prolapse and is easy to underestimate.
• LV size and EF (end-systolic diameter, end-diastolic diameter, Simpson biplane), left atrial volume index (LA enlargement marks chronic MR burden and predicts postoperative LV dysfunction after repair), and pulmonary artery systolic pressure from tricuspid regurgitation velocity (over 50 mmHg defines pulmonary hypertension in flail-leaflet MR, which roughly doubles mortality risk).^[27][21]
• 24 to 48 hour Holter (or 14-day patch) for any symptom or risk stratification — PVC burden, NSVT, PSVT, paroxysmal AF. A high PVC burden and NSVT mark arrhythmic MVP: in the papillary-muscle ablation series the mean PVC burden was 24 percent, and PVC-triggered VF was the presenting event in 4 of 25 patients.^[25][24]
• Cardiac MRI with late gadolinium enhancement for arrhythmic MVP, syncope or a family history of SCD — to detect inferolateral basal and papillary-muscle fibrosis.^[22][20]
• Signal-averaged ECG (late potentials) and TOE plus 3D TTE/TOE for preoperative repair planning (leaflet segmentation A1 to A3, P1 to P3). Cross-sectional aortic imaging is added only when connective-tissue disease is present.^[8][10]

Two drug-dose lists to carry into the viva, verbatim with their cites:^[29][26]

• Symptomatic palpitations or atypical chest pain — beta-blockade is the established first-line therapy for the symptomatic phenotype; propranolol was the original evidence — in 16 patients, 6 (37 percent) improved overall, almost entirely through less palpitation, while chest pain was relieved in only 2 of 8, fatigue did not improve and appeared de novo in 3, and 3 (19 percent) deteriorated. Modern practice uses metoprolol or bisoprolol titrated to response, with verapamil when a beta-blocker is not tolerated.^[29]
• Ventricular arrhythmia in arrhythmic MVP — catheter ablation of papillary-muscle or fascicular PVCs achieves complete elimination or major burden reduction in most cases and can reverse PVC-mediated cardiomyopathy; ICD for secondary prevention after cardiac arrest or sustained VT.^[25][23]

Two emergencies that do need resuscitation

Most MVP patients never need acute care — but two presentations do, and both are surgical.^[1]

1. Acute severe MR from chordal rupture (the fibroelastic-deficiency presentation). Sudden posterior or anterior leaflet flail produces sudden severe MR, flash pulmonary oedema and cardiogenic shock in the unprepared ventricle. The bedside triad is sudden dyspnoea, a new loud pan-systolic murmur (often with thrill), and acute decompensated heart failure in a previously well patient.^[1]

• Resuscitate: ABCDE and oxygen, large-bore IV access, IV loop diuretic for pulmonary oedema, afterload reduction to increase forward flow (the unprepared ventricle in acute severe MR gains total output as wall tension falls — the physiological rationale for vasodilators), inotropes if hypotensive, an intra-aortic balloon pump for haemodynamic support when surgery is imminent, and non-invasive or invasive ventilation.^[28][9]
• Urgent TTE plus or minus TOE to confirm anatomy, then early mitral valve surgery — repair is preferred and acute primary MR typically demands it before decompensation; percutaneous edge-to-edge repair (MitraClip) is an accepted alternative in emergency situations with high surgical risk.^[9][10]

2. Out-of-hospital cardiac arrest or polymorphic VT in arrhythmic MVP with MAD. Standard ACLS — high-quality CPR, defibrillation for VF, and an antiarrhythmic drug for shock-refractory VF or pulseless VT: the ALPS trial protocol specified up to 450 mg of amiodarone IV or up to 180 mg of lidocaine IV versus placebo in the field, each given after at least one shock and once vascular access was established. Survival to hospital discharge was 24.4 percent with amiodarone, 23.7 percent with lidocaine and 21.0 percent with placebo — neither drug improved survival or neurological outcome overall, but among bystander-witnessed arrests the active drugs did beat placebo. After ROSC, manage in a cardiac ICU with targeted temperature management and ICD evaluation for secondary prevention.^[26][11][12]

The stepped, risk-stratified plan

MVP management is staged by MR severity, LV and LA consequences, rhythm, and the arrhythmic phenotype — not by the click.^[1][2][3]

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Step 1 — Asymptomatic, no MR or only mild MR. Reassure, advise lifestyle and good dental hygiene, give no antibiotics for routine procedures — MVP is not a highest-risk condition in the AHA list, and NICE goes further: it classes acquired valve disease with regurgitation as "increased risk" yet still does not recommend routine antibiotic prophylaxis for dental or other listed procedures. Repeat echo in 3 to 5 years unless symptoms change.^[30][1]

Step 2 — Symptomatic palpitations, atypical chest pain, mild-moderate MR. Beta-blocker first line — the original data are propranolol's (overall improvement in 6 of 16 patients, driven by palpitation relief, with deterioration in 3); modern practice titrates metoprolol or bisoprolol to response, with verapamil when a beta-blocker is not tolerated. Treat coexisting anxiety or panic; reassure about the overall benign prognosis.^[29][1]

Step 3 — Arrhythmic MVP with complex PVCs or NSVT. Optimise beta-blockade; consider catheter ablation of papillary-muscle or fascicular PVCs — complete elimination or major burden reduction in most series, with reversal of PVC-mediated cardiomyopathy; ICD for secondary prevention after cardiac arrest or sustained VT. The EHRA consensus advocates individualised risk stratification for primary-prevention ICD (family history of SCD, syncope, NSVT, LGE on MRI).^[25][23][16]

Step 4 — Severe primary MR reaching a surgical trigger. This is the decision that matters, and the 2020 ACC/AHA wording is exact. Class 1: mitral valve intervention in symptomatic severe primary MR (Stage D) irrespective of LV systolic function; and mitral valve surgery in asymptomatic severe primary MR with LV systolic dysfunction, defined as LVEF 60 percent or less or LVESD 40 mm or more (Stage C2). Note the boundaries: the guideline benchmark is LVEF ≤60 percent and LVESD ≥40 mm, not "under 60" and "over 40". Class 2a: repair in asymptomatic severe primary MR with normal LV function (LVEF ≥60 percent and LVESD ≤40 mm, Stage C1) when a successful durable repair without residual MR is more than 95 percent likely with an expected mortality under 1 percent at a Primary or Comprehensive Valve Center. Class 2b: surgery may be considered in Stage C1 when LV size rises or EF falls across three or more serial studies. New-onset AF and a resting PASP over 50 mmHg were Class IIb triggers in the 2014 guideline and are not intervention triggers in the 2020 document.^[30][31][17]

^{[30] [31] [21]}

Type of operation. Mitral valve repair is preferred over replacement — better event-free survival, freedom from reoperation, better LV preservation, and avoidance of anticoagulation in patients without AF; durable repair before dysfunction restores normal life expectancy. Techniques include triangular or quadrangular resection of the prolapsing segment, neochordoplasty with artificial PTFE chordae, and ring or band annuloplasty. Replacement (bioprosthesis, or mechanical for chronic AF needing long-term anticoagulation) is reserved for repair failure, extensive calcification, or the elderly.^[18][17]

Anticoagulation for AF is standard, CHA2DS2-VASc-driven, with a NOAC preferred over warfarin when there is no mechanical valve or moderate mitral stenosis. Endocarditis prophylaxis is restricted to the highest-risk subset. The 2020 ACC/AHA list (Class 2a, and only for dental procedures involving gingival or periapical manipulation or perforation of the oral mucosa) is: prosthetic cardiac valves including transcatheter prostheses and homografts; prosthetic material used for valve repair such as annuloplasty rings, chords or clips; previous infective endocarditis; unrepaired cyanotic congenital heart disease, or repaired congenital heart disease with residual shunts or valvular regurgitation at or adjacent to a prosthetic patch or device; and cardiac transplant with valve regurgitation from a structurally abnormal valve. MVP is NOT in this list, at any degree of MR — but a patient who has had mitral repair with an annuloplasty ring is, so the answer changes after surgery. The same recommendation explicitly does not apply to non-dental procedures (TOE, endoscopy, colonoscopy, cystoscopy) in the absence of active infection. The AHA reviewed the evidence in 2021 and made no change to the 2007 highest-risk categories, but it did change the drugs: clindamycin is no longer recommended as an alternative for penicillin allergy (cephalexin, azithromycin, clarithromycin or doxycycline instead).^[30][13]

Surveillance: TTE annually for moderate MR or asymptomatic severe MR, 3 to 5 yearly for mild MR, and immediately for any new symptom.^[1]

The scenarios that change the answer

• Fibroelastic deficiency with acute chordal rupture — sudden severe MR; urgent repair with neochordoplasty plus annuloplasty. Where leaflet dysfunction is limited enough that only annuloplasty and posterior-leaflet repair are needed, the guideline cites an operative mortality under 1 percent, long-term survival equal to the age-matched population, about 95 percent freedom from reoperation and over 80 percent freedom from recurrent moderate or severe MR at 15 to 20 years.^[30]
• Diffuse Barlow disease with chronic severe MR — bileaflet, multi-segmental; anterior or bileaflet disease needs complex extensive repair and durability is less certain: freedom from reoperation about 80 percent and freedom from recurrent moderate or severe MR about 60 percent at 15 to 20 years, still better than replacement when done at a high-volume centre.^[30]
• MASS phenotype — mitral prolapse plus aortic-root dilation plus skeletal and skin features in a marfanoid patient who does not meet Ghent criteria; monitor the aortic root, screen the family.^[33]
• Arrhythmic MVP with MAD and cardiac arrest or sustained VT — ICD for secondary prevention, beta-blockade, amiodarone, catheter ablation for drug-refractory arrhythmia; mitral repair may reduce arrhythmia burden in selected patients.
• MVP with new-onset AF — anticoagulate per CHA2DS2-VASc; rate or rhythm control; surgery for severe MR plus MAZE or pulmonary-vein isolation at repair.
• MVP with endocarditis — Duke criteria apply; three blood cultures, TTE then TOE, intravenous antibiotics per local protocol; early surgery for heart failure, uncontrolled infection, embolic phenomena or vegetations over 10 mm.^[3][4]

How MVP patients come to harm — the preventable list

• Reassuring the arrhythmic phenotype as benign and missing bileaflet prolapse with MAD, inferior TWI and complex PVCs — the preventable sudden death.^[3]
• Reading the eccentric, wall-hugging MR jet as "mild" on colour Doppler and under-grading severe MR — quantify with PISA, vena contracta and EROA.^[1]
• Waiting for the EF to fall below 50 in MR — by then the ventricle has decompensated and may not recover; the guideline benchmark is LVEF 60 percent or less.^[30]
• Treating "palpitations" as pure anxiety and stopping there — beta-blockade is the rational first line for the symptomatic phenotype, and a Holter is what separates benign ectopy from the arrhythmic phenotype.^[29][25]
• Confusing the HOCM murmur with the MVP click — the Valsalva and squatting responses are opposite; get them right.^[1]
• Giving endocarditis prophylaxis for routine MVP — MVP is not one of the highest-risk conditions; conversely, forgetting that a previous repair with an annuloplasty ring does put the patient in that list.^[30]
• Sending diffuse Barlow disease to a low-volume centre where repair fails and the patient gets a replacement they did not need.^[1]

Prognosis, disposition, and what to tell the patient

The prognosis of MVP is usually benign, but it is heterogeneous and may be severe. Most patients have mild MR, a normal life expectancy, and never need surgery — but the community data separate an excellent-prognosis majority from subsets with high morbidity or frankly excess mortality. The clinical task is to identify the high-risk subsets and act.^[32]

• Mild MR, asymptomatic, 0 or 1 secondary risk factor — 10-year mortality 5 ± 2 percent (no different from expected) and MVP-related events 0.2 percent per year; follow-up every 3 to 5 years.
• Moderate MR, or two or more secondary risk factors — close follow-up and re-imaging 1 to 2 yearly; MVP-related events run at 1.7 percent per year with high cardiovascular morbidity (6.2 percent per year), though overall mortality is still no different from expected.
• Moderate-to-severe MR, or EF under 50 percent (a primary risk factor) — 10-year mortality 45 ± 9 percent and MVP-related events 15 percent per year; this is the group that must not be left unoperated, and surgery restores life expectancy when done before LV dysfunction sets in.
• Severe MR after repair — in an asymptomatic-MR repair series, in-hospital mortality was 0.96 percent, survival 90.4 percent at 10 years, and freedom from recurrent moderate or severe MR 83.6 percent at 10 years.^[32][27]
• Arrhythmic MVP with MAD after cardiac arrest — high recurrence; ICD improves survival.^[1][3]

Disposition: asymptomatic MVP is outpatient follow-up at the echo intervals above; symptomatic or severe MR belongs in a valve clinic with cardiology, cardiac surgery and imaging; acute severe MR, syncope or pulmonary oedema is admitted for medical stabilisation and surgical decision; cardiac arrest or sustained VT goes to a cardiac ICU or arrhythmia service for ICD evaluation.^[1][2][3]

What to tell the patient: most MVP is benign; avoid dehydration, stay active, report any new breathlessness, palpitation or syncope immediately, and keep good dental hygiene. The reassurance matters — a label of "heart disease" handed to an anxious young person can do more harm than the valve.^[1]

Special populations

Pregnancy — most MVP is well tolerated. The 2020 guideline makes beta-blockers Class 2a for rate control or arrhythmia in pregnant women with valve disease and diuretics Class 2a for volume overload with heart-failure symptoms, while ACE inhibitors and ARBs are Class 3: Harm because of fetal risk (the ACE-inhibitor labels carry a boxed fetal-toxicity warning). Surgery in pregnancy carries high fetal risk and is reserved for refractory cases, preferably postpartum.^[30]

Athletes — asymptomatic MVP with no or mild MR and no secondary risk factors carries MVP-related events of about 0.2 percent per year, so it is not in itself a bar to competitive sport; MVP with severe MR, LV dilatation, documented ventricular arrhythmia or the arrhythmic phenotype needs specialist assessment before clearance, because those are the patients the high-risk pathway is built for. At the bedside the murmur, not the echo, is what gets confused with HOCM — use the manoeuvre response.^[32][23]

Marfan and connective-tissue disease — image the aortic root serially, and treat with either a beta-blocker or an angiotensin receptor blocker at maximally tolerated dose (the 2022 aortic guideline recommends one or the other, not necessarily both). Root and ascending replacement is recommended at an aortic root diameter of 50 mm or more, and is reasonable at 45 mm or more with high-risk features (family history of dissection, rapid growth, diffuse root and ascending dilatation, marked vertebral artery tortuosity) or a cross-sectional root area to height ratio of at least 10 cm²/m. In Marfan, MVP penetrance rises from 43 percent at age 30 to 77 percent by 60, but outcome is dominated by aortic risk.^[34][33]

Elderly — fibroelastic deficiency predominates and chordal rupture is a common presentation; repair is still preferred, and repair results are superior to replacement at high-volume centres even in elderly patients. Transcatheter edge-to-edge repair (TEER) is Class 2a in severely symptomatic patients (NYHA III or IV) with severe primary MR and high or prohibitive surgical risk, if valve anatomy is favourable and life expectancy is at least 1 year.^[30][10]

Children — MVP is uncommon and more often syndromic (Marfan and the other heritable connective-tissue disorders); familial clustering is well described in myxomatous MVP, so screening echocardiography of first-degree relatives is reasonable where the family form is severe or recurrent.^[33]

The evidence and the regions

The 2020 ACC/AHA guideline (Otto et al.), which replaced the 2014 AHA/ACC guideline (Nishimura et al.), sets the Class 1 surgical triggers for severe primary MR and the Class 2a endocarditis-prophylaxis position; the 2022 EHRA consensus (Sabbag et al.) is the modern authority on arrhythmic MVP and MAD. Freed et al. (1999) fixed the community prevalence at 2.4 percent in the Framingham offspring cohort and Avierinos et al. (2002) the risk-stratified natural history in Olmsted County. Barlow and Pocock (1979) anchored the diffuse phenotype, and Carmo et al. (2010) showed that MAD is common in myxomatous MVP and measurable on plain transthoracic echo.^{[30][31][3][1][32][19][4]}

Regional deltas: the framework (echo diagnosis, dynamic manoeuvres, repair-preferred surgery) is globally consistent. In India and resource-limited settings, rheumatic mitral disease dominates and Barlow-type myxomatous MVP is relatively less common; the backbone of MVP therapy is reassurance, beta-blockade, and mitral repair at the trigger. Access to cardiac MRI for arrhythmic-MVP risk stratification and to high-volume mitral-repair centres varies, which is why the bedside markers (bileaflet prolapse on TTE, MAD, inferior TWI, frequent complex PVCs) matter most where MRI is scarce.^[24][22]

The mantra, and the mnemonic

^{[30] [35]}

The mantra: click earlier with Valsalva, later with squatting; most patients never need surgery, but the arrhythmic phenotype can kill.^[35][22]

Ward-round test — three stems, thirty seconds each

Stem 1 — the woman from the top of the topic (answer)ShowHide

The 28-year-old with a mid-systolic click and late systolic murmur that moves earlier on standing and later on squatting, mild palpitations and atypical chest pain. Echo shows bileaflet MVP, mild MR, normal LV, no MAD. What do you tell her, and what do you do? Model: This is benign classic MVP — the manoeuvre response is diagnostic (earlier with reduced preload, opposite to HOCM). Reassure her about the prognosis, advise good dental hygiene and hydration, prescribe a beta-blocker for the symptomatic palpitations and atypical chest pain (the original evidence is propranolol, an uncontrolled series of 16 patients; modern practice titrates metoprolol or bisoprolol), treat any coexisting anxiety, and arrange surveillance echo in 3 to 5 years. Do not give endocarditis prophylaxis for routine procedures — it is restricted to the highest-risk subset, and MVP is not in it. Tell her to report any new breathlessness, syncope or sustained palpitations immediately.^[29][13][1]

Stem 2 — sudden breathlessness and a new murmur (answer)ShowHide

A 62-year-old man who was well yesterday presents with acute pulmonary oedema and a new loud pan-systolic murmur with a thrill at the apex. He has a history of a "click" found years ago. What happened, and what is the first 15 minutes? Model: This is acute severe MR from chordal rupture on a fibroelastic-deficiency valve. Sit upright, give high-flow oxygen and non-invasive ventilation and an IV loop diuretic for the pulmonary oedema, and cut afterload with an IV vasodilator — in the unprepared ventricle of acute MR, falling wall tension increases total LV output, and an intra-aortic balloon pump supports the same principle when hypotension blocks vasodilators. Confirm with urgent TTE plus or minus TOE, then arrange early mitral valve surgery — acute primary MR typically demands it before decompensation. Do not reach for afterload reduction without securing the airway and circulation first.^[28][9]

Stem 3 — the young woman who collapsed (answer)ShowHide

A 34-year-old woman with known MVP is admitted after an out-of-hospital cardiac arrest, successfully resuscitated. Her ECG shows T-wave inversion in II, III and aVF; Holter shows frequent complex PVCs and runs of non-sustained VT; cardiac MRI shows late gadolinium enhancement at the inferolateral LV base. What is the diagnosis and the next step? Model: This is arrhythmic MVP with mitral annular disjunction — bileaflet prolapse plus MAD plus inferolateral basal and papillary-muscle fibrosis (the LGE on her MRI), driving polymorphic VT and sudden cardiac arrest; this phenotype is usually a young woman with only mild-to-moderate MR. After stabilisation in a cardiac ICU she needs an ICD for secondary prevention — survivors of VF or haemodynamically significant sustained VT live longer with an ICD than with antiarrhythmic drugs alone. Refer to a tertiary valve-and-arrhythmia service; catheter ablation of papillary-muscle PVCs eliminates or markedly reduces ectopy in most series; and reassess the mitral valve for repair if severe MR coexists — both ablation and repair may lower arrhythmic risk. This is the exception that makes MVP an exam topic at all.^[22][16][25]

References38ShowHide

1. [1]Freed LA, Levy D, Levine RA, et al. Prevalence and clinical outcome of mitral-valve prolapse N Engl J Med, 1999.PMID 10387935
2. [2]Narayanan K, Uy-Evanado A, Teodorescu C, et al. Mitral valve prolapse and sudden cardiac arrest in the community Heart Rhythm, 2016.PMID 26416619
3. [3]Sabbag A, Essayagh B, Barrera JA, et al. EHRA expert consensus statement on arrhythmic mitral valve prolapse and mitral annular disjunction complex in collaboration with the ESC Council on valvular heart disease and the European Association of Cardiovascular Imaging endorsed by the Heart Rhythm Society, by the Asia Pacific Heart Rhythm Society, and by the Latin American Heart Rhythm Society Europace, 2022.PMID 35951656
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