Echo Reference — Valve Regurgitation
Mitral Regurgitation: Echo Assessment and Severity Grading
Echo criteria for grading mitral regurgitation — vena contracta, EROA, regurgitant volume and regurgitant fraction — with mechanism classification, a PISA calculator, measurement pitfalls and an approach to discordant findings.
Severity Criteria at a Glance
Chronic MR is graded mild, moderate or severe; quantitative measures divide the intermediate range in two, giving four grades. The same thresholds apply to primary and secondary MR, with a caveat in secondary MR.
Quantitative Criteria
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| Parameter | Mild (grade I) | Moderate (grade II) | Moderate–severe (grade III) | Severe (grade IV) |
|---|---|---|---|---|
| EROA (cm²) | < 0.20 | 0.20–0.29 | 0.30–0.39 | ≥ 0.40 |
| RVol (mL/beat) | < 30 | 30–44 | 45–59 | ≥ 60 |
| RF (%) | < 30 | 30–39 | 40–49 | ≥ 50 |
EROA, effective regurgitant orifice area; RVol, regurgitant volume; RF, regurgitant fraction. ASE 2017 [1]; the severe thresholds are shared by the 2020 ACC/AHA [3] and 2025 ESC/EACTS [2] guidelines. RVol may be lower than expected in low-flow states.
Qualitative and Semi-quantitative Criteria
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| Parameter | Mild | Moderate | Severe |
|---|---|---|---|
| Valve morphology | Normal or mildly abnormal leaflets | Moderately abnormal leaflets or moderate tenting | Flail leaflet, ruptured papillary muscle, severe retraction, large perforation, or severe tenting with poor coaptation |
| LV and LA size | Usually normal | Normal or mildly dilated | Dilated in chronic MR |
| Colour jet area | Small, central, narrow, often brief | Variable | Large central jet (> 50% of LA area), or an eccentric wall-impinging jet of variable size |
| Flow convergence | Not visible, transient or small | Intermediate in size and duration | Large throughout systole |
| CW Doppler jet | Faint, partial or parabolic | Dense, but partial or parabolic | Dense and holosystolic; may be triangular |
| Vena contracta width (mm) | < 3 | 3–6.9 | ≥ 7 (> 8 for biplane) |
| Pulmonary vein flow | Systolic dominance | Normal or systolic blunting | Minimal or no systolic flow, or systolic flow reversal |
| Mitral inflow | A-wave dominant | Variable | E-wave dominant (> 1.2 m/s) |
ASE 2017 [1]. Each sign has confounders — see limits of individual parameters.
Abbreviations and definitions
| Term | Meaning |
|---|---|
| VC — vena contracta | The narrowest neck of the regurgitant jet, immediately downstream of the anatomical orifice. |
| PISA — proximal isovelocity surface area | The flow convergence zone on the ventricular side of the valve, used to calculate regurgitant flow rate. |
| EROA — effective regurgitant orifice area | The cross-sectional area of the vena contracta: the effective size of the leak, smaller than the anatomical opening. In cm². |
| RVol — regurgitant volume | The volume regurgitated per beat, in mL. |
| RF — regurgitant fraction | The proportion of total LV stroke volume that is regurgitated, in %. |
Interpretation of the Thresholds in Secondary MR
ASE 2017, ACC/AHA 2020 and ESC/EACTS 2025 apply the same severe thresholds to primary and secondary MR. In secondary MR the numbers tend to read low: an elliptical orifice makes 2D PISA underestimate EROA, and a low forward stroke volume lowers RVol for a given regurgitant fraction.
Severity is assessed after medical therapy has been optimised (and cardiac resynchronisation where indicated), with the patient euvolaemic and normotensive; secondary MR is load-dependent and often falls with treatment. Severity and eligibility for intervention are separate questions: in COAPT, qualifying MR was determined by a tiered, multiparametric core-laboratory algorithm, and EROA ≥ 0.30 cm² was not an obligatory criterion [6, 7].
Primary, Ventricular Secondary and Atrial Secondary MR
The mechanism determines how the numbers are interpreted and which treatment is relevant. Primary MR is disease of the valve apparatus itself. Secondary MR occurs with structurally normal leaflets and results from ventricular or atrial remodelling.
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| Feature | Primary | Ventricular secondary | Atrial secondary |
|---|---|---|---|
| Underlying problem | Leaflets, chordae or papillary muscles | LV dilatation or dysfunction displacing the papillary muscles | LA and annular dilatation with insufficient leaflet coverage |
| Typical setting | Prolapse or flail, rheumatic disease, endocarditis, annular calcification, radiation, congenital cleft | Ischaemic or non-ischaemic cardiomyopathy | Long-standing AF, heart failure with preserved ejection fraction |
| Leaflets | Abnormal: redundant, flail, thickened, perforated or restricted | Structurally normal; tethered apically, with tenting | Structurally normal; flat coaptation with little tenting |
| Annulus | Variable; dilates late | Dilated, secondary to LV remodelling | Dilated; often the dominant abnormality |
| Left ventricle | Normal until volume overload develops | Dilated and/or reduced LVEF; regional wall motion abnormality when ischaemic | Normal or near-normal size, LVEF ≥ 50%, no regional wall motion abnormality |
| Jet | Often eccentric, directed away from a prolapsing or flail leaflet | Central with symmetric tethering; posteriorly directed with asymmetric posterior tethering | Usually central |
| Usual Carpentier type | II or IIIa; I with perforation or cleft | IIIb | I |
Atrial Secondary MR
Atrial secondary MR can be haemodynamically important despite a preserved LVEF and little LV enlargement. It is easily mislabelled as primary MR, or discounted because the ventricle looks normal. Criteria commonly used to identify it are an LVEF ≥ 50% without regional wall motion abnormality, no or minimal LV dilatation (LVEDD < 56 mm in women, < 63 mm in men), annular dilatation (anteroposterior diameter > 35 mm) and LA dilatation (LAVI > 34 mL/m²), with structurally normal leaflets [2, 9]. In advanced disease the atrial and ventricular phenotypes overlap.
Carpentier Classification
Carpentier's classification describes leaflet motion. It does not map directly onto primary versus secondary MR, so mechanism and aetiology are reported separately.
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| Type | Leaflet motion | Mechanism | Examples | Aetiological category |
|---|---|---|---|---|
| I | Normal | Annular dilatation, leaflet perforation or cleft | Atrial secondary MR (AF, HFpEF); endocarditis with perforation; congenital cleft | Secondary with annular dilatation; primary with perforation or cleft |
| II | Excessive | Prolapse or flail: the free edge overrides the annular plane | Myxomatous degeneration, fibroelastic deficiency, chordal rupture, papillary muscle rupture | Usually primary |
| IIIa | Restricted in systole and diastole | Leaflet and subvalvular thickening, retraction or fusion | Rheumatic disease, radiation, drug-induced valvulopathy | Usually primary |
| IIIb | Restricted in systole only | Apical and lateral papillary muscle displacement tethering the leaflets | Ischaemic cardiomyopathy, dilated cardiomyopathy | Ventricular secondary |
Approach to Severity Assessment
The following is a practical approach adapted from the ASE 2017 algorithm for chronic MR [1]. It is not a vote among parameters: the algorithm looks first for specific criteria, then relies on quantification.
Specific criteria for mild MR
VC width ≤ 3 mm
PISA radius absent or ≤ 0.3 cm (Nyquist 30–40 cm/s)
Mitral inflow A-wave dominant
Soft or incomplete CW jet
Normal LV and LA size
Specific criteria for severe MR
VC width ≥ 7 mm
PISA radius ≥ 1.0 cm (Nyquist 30–40 cm/s)
Central large jet > 50% of LA area
Pulmonary vein systolic flow reversal
Enlarged LV with normal function
Measurement Technique
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| Measurement | Method | Key limitation |
|---|---|---|
| Vena contracta width | Single plane: parasternal long-axis or apical four-chamber view, zoomed, Nyquist 50–70 cm/s; the narrowest neck of the jet, between flow convergence and jet expansion. Biplane: the average of near-orthogonal four-chamber and two-chamber measurements, preferred when the jet is elliptical, as in secondary MR. |
An elliptical jet is genuinely wider along the coaptation line, seen in the two-chamber view, so a single plane misjudges it. The biplane average is separate from averaging two to three beats in each view. Not valid for multiple jets. |
| PISA radius | Apical four-chamber view, zoomed; colour baseline shifted in the direction of the jet to an aliasing velocity of 30–40 cm/s. From the first aliasing boundary to the regurgitant orifice at the centre of flow convergence, at the time of peak MR velocity. | Squared in the calculation, and valid only for a hemispheric shell. |
| CW Doppler | Beam aligned with the jet; peak velocity and VTI from a complete envelope. | Peak MR velocity is usually 4–6 m/s; values outside this range suggest poor alignment or an unusual LV–LA gradient. |
| Volumetric method | RVol = mitral stroke volume (annular diameter, PW Doppler at the annulus) − LVOT stroke volume. RF = RVol ÷ mitral stroke volume. Suited to multiple or eccentric jets. | Diameter errors are squared; the LVOT comparison is invalid with more than mild aortic regurgitation. |
ASE 2017 [1] and BSE 2021 [5].
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Limits of Individual Parameters
| Parameter | Caveat |
|---|---|
| Colour jet area | Varies with driving pressure, LA size, gain and Nyquist limit. A wall-adherent jet can look deceptively small, but eccentricity alone does not set a minimum severity; a large jet wrapping around the atrium still requires integration. |
| Vena contracta width | Narrow range of values, so small errors change the grade. A single plane misjudges an elliptical orifice. |
| CW Doppler | Density is qualitative. A triangular, early-peaking envelope reflects rapid LV–LA pressure equalisation: it supports severe MR, but is not required in chronic severe MR with a compliant LA. |
| Pulmonary vein flow | Systolic blunting is not synonymous with moderate MR: it also occurs with AF, raised LA pressure and LV dysfunction. Systolic reversal is specific but insensitive, and may affect one vein only. |
| Mitral inflow | E velocity > 1.2 m/s supports significant MR only without mitral stenosis, and varies with filling pressure, diastolic function and rhythm. A-wave dominance makes severe MR unlikely. |
| LV and LA size | Dilatation has other causes. Normal chambers do not exclude acute severe MR. |
PISA Calculator: EROA and Regurgitant Volume
The PISA method assumes that flow converges on the orifice in hemispheric shells of equal velocity, and that flow through a shell equals flow through the orifice.
EROA and RVol by PISA
Enter the PISA radius, aliasing velocity and peak MR velocity. MR VTI adds regurgitant volume. In secondary MR, the result is read with the threshold caveat.
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PISA Pitfalls
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| Pitfall | Effect |
|---|---|
| Non-hemispheric convergence | Errors run both ways. An elliptical orifice, typical of secondary MR, flattens the shell and EROA is underestimated; a zone constrained by the LV wall or a leaflet is pushed outward and EROA is overestimated. |
| Angle correction | For wall constraint only: EROA × (α ÷ 180), which lowers it. It does not correct an elliptical or irregular zone, where 3D colour Doppler or the volumetric method is preferred. |
| Aliasing velocity | The formula includes the aliasing velocity, so a higher setting does not in itself underestimate EROA. A small radius magnifies a 1 mm error; a very low setting gives a large, distorted shell. |
| Radius measurement | Squared in the formula. Taken to the regurgitant orifice at the centre of flow convergence, in the same frame, along the direction of flow. |
| Timing | Radius and velocity belong to the same moment — by convention the time of peak MR velocity, usually mid-systole. A single frame is unrepresentative when the shell changes through systole. |
| Dynamic secondary MR | The orifice is typically largest in early and late systole and smallest in mid-systole, when LV pressure and closing force peak. A mid-systolic radius can understate the regurgitant burden. |
| Late-systolic MR in prolapse | The orifice is present for only part of systole, so a large peak EROA overstates the regurgitant burden; RVol or volumetric quantification is more representative. Jet timing is shown by colour M-mode or the CW envelope [8]. |
| Multiple jets | PISA addresses one jet, and values are not simply additive. The volumetric method or 3D vena contracta area is preferred. |
| Irregular rhythm | In AF or with frequent ectopy, several beats are averaged and post-ectopic beats avoided. |
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Discordant Findings: What to Recheck
When EROA, RVol, colour Doppler and chamber response disagree, the measurements are rechecked before a grade is assigned.
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| Finding | Likely explanations | Recheck |
|---|---|---|
| Large EROA, small RVol | Non-holosystolic MR; short or mistraced VTI; low-flow state | Jet duration on colour M-mode and CW; VTI tracing; report RVol with the timing |
| Small colour jet, large VC or EROA | Eccentric wall-adherent jet; acute MR with high LA pressure; low colour gain | Multiple views; flow convergence; pulmonary veins |
| Large colour jet, small EROA | High driving pressure (hypertension, aortic stenosis, LVOT obstruction); low Nyquist limit; radius taken in the wrong frame | Nyquist 50–70 cm/s for jet area; blood pressure; repeat PISA |
| Quantitatively severe, normal LV and LA | Acute MR; overestimation from constrained PISA or non-holosystolic MR; small body size | Jet timing; convergence angle; volumetric cross-check; CMR if unresolved |
| Dilated LV or LA, quantitatively mild to moderate | Another cause of dilatation (cardiomyopathy, AF, aortic regurgitation); underestimation with an elliptical orifice; MR assessed when well offloaded | Mechanism; 3D vena contracta area; exercise echocardiography; CMR |
| PISA and volumetric results disagree | Annular or LVOT diameter error; aortic regurgitation; multiple jets; non-hemispheric convergence | Diameters remeasured; reliance on the method whose assumptions are met |
| Grade differs from a previous study | Change in blood pressure, volume status, rhythm, sedation or anaesthesia | Blood pressure, rhythm and study conditions recorded in both reports |
Acute MR and Other Difficult Situations
Acute Severe MR
Acute severe MR — from chordal or papillary muscle rupture, or leaflet perforation in endocarditis — behaves differently from chronic MR. The LA has not had time to dilate, so LA pressure rises steeply and the LV–LA gradient collapses late in systole. The CW envelope is often triangular and early-peaking with a low peak velocity, and the colour jet may be brief and deceptively small.
The LV and LA may remain normal in size, although pre-existing disease can alter the appearance. A hyperdynamic LV is common but not obligatory: LV function may be reduced when the cause is infarction. Pulmonary oedema or shock with a flail leaflet or ruptured papillary muscle, a large flow convergence and pulmonary vein systolic reversal point to the diagnosis. TOE is indicated when transthoracic imaging does not explain the clinical picture.
3D Vena Contracta Area
3D colour Doppler allows planimetry of the narrowest cross-section of the jet, the vena contracta area (VCA). Its strength is fewer geometric assumptions: it does not assume a circular orifice or hemispheric convergence, which suits elliptical orifices in secondary MR and multiple jets. It measures the jet rather than the anatomical defect, and remains subject to haemodynamic conditions, colour gain, blooming and limited spatial and temporal resolution. Cut-offs are less well validated than for 2D methods; a VCA of about 0.4 cm² or more has been associated with severe MR [1, 4].
Loading Conditions
MR severity varies with blood pressure, volume status, rhythm and anaesthesia. Blood pressure and rhythm are recorded at the time of the study. General anaesthesia lowers afterload, and intra-operative TOE commonly underestimates MR.
Role of TOE, CMR and Exercise Echocardiography
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| Test | Question it answers | Where it helps |
|---|---|---|
| TOE, with 3D | What is the anatomy and mechanism, and is the valve suitable for repair or a transcatheter procedure? | Inconclusive transthoracic study; suspected flail, perforation or endocarditis; planning of surgical repair or transcatheter edge-to-edge repair. Sedation may reduce apparent severity. |
| CMR | How much regurgitation is there, and how large are the chambers? | Discordant or unreliable echo quantification. RVol is derived from LV stroke volume minus aortic forward flow, independent of jet geometry, with accurate LV and RV volumes and fibrosis assessment. CMR and echo values are not interchangeable. |
| Exercise echocardiography | Do symptoms or haemodynamics change with exertion? | Symptoms out of proportion to resting MR, or apparently asymptomatic severe MR: exercise capacity, dynamic increase in MR and exercise-induced pulmonary hypertension. |
EACVI 2022 [4] and ESC/EACTS 2025 [2].
Reporting Checklist and Clinical Implications
| Item | Content |
|---|---|
| Mechanism | Primary, ventricular secondary or atrial secondary; Carpentier type; affected scallops in prolapse or flail |
| Jet | Number, direction (central or eccentric) and duration (holosystolic or late systolic) |
| Semi-quantitative | VC width, flow convergence, CW density and shape, pulmonary vein flow, mitral E velocity |
| Quantitative | EROA, RVol and RF, with the method used (PISA, volumetric or 3D) |
| Left ventricle | LVEDD and LVESD, absolute and indexed; volumes and LVEF; regional wall motion |
| Left atrium | Indexed LA volume |
| Right heart | Estimated systolic pulmonary artery pressure, RV size and function, tricuspid regurgitation severity |
| Study conditions | Blood pressure, heart rate and rhythm, image quality |
| Conclusion | Integrated grade, confidence in it, change from the previous study, and whether further imaging is advised |
LVEF of 60% in Severe Primary MR
In severe MR the LV ejects into two outlets, one of them the low-pressure LA, so LVEF overstates contractile function. A value at the lower end of the conventional normal range already indicates LV dysfunction in this setting and is associated with worse LV function and survival after surgery. Intervention thresholds are therefore set at LVEF ≤ 60% or LVESD ≥ 40 mm (ESC/EACTS 2025 also accepts indexed LVESD ≥ 20 mm/m²), not at conventionally abnormal values.
Findings That Prompt Valve-team Assessment in Severe Primary MR
Referral and a Class I indication for surgery are different thresholds. A single marker below is enough to prompt valve-team assessment; the ESC/EACTS Class I pathway for asymptomatic patients requires at least three. Preserved LV means LVEF > 60%, LVESD < 40 mm and indexed LVESD < 20 mm/m².
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| Finding | Class | Guideline position |
|---|---|---|
| Symptoms attributable to MR | I | Intervention recommended (ACC/AHA 2020, ESC/EACTS 2025). |
| LV dysfunction without symptoms | I | Surgery recommended with LVEF ≤ 60% or LVESD ≥ 40 mm (ACC/AHA 2020, ESC/EACTS 2025). ESC/EACTS 2025 also accepts indexed LVESD ≥ 20 mm/m². |
| No symptoms, preserved LV: pulmonary hypertension or AF | IIa | ESC/EACTS 2025: surgery should be considered with resting SPAP > 50 mmHg, or AF secondary to MR. |
| No symptoms, preserved LV: significant LA dilatation | IIa | ESC/EACTS 2025: repair should be considered in low-risk patients with LAVI ≥ 60 mL/m² or LA diameter ≥ 55 mm, when performed in a Heart Valve Centre and a durable repair is likely. |
| No symptoms, preserved LV: at least three markers | I | ESC/EACTS 2025: repair recommended in low-risk patients when a durable repair is likely and at least three are present — AF; resting SPAP > 50 mmHg; LA dilatation (LAVI ≥ 60 mL/m² or diameter ≥ 55 mm); at least moderate secondary tricuspid regurgitation. |
| No symptoms, preserved LV: repairable valve | 2a | ACC/AHA 2020: repair is reasonable at a Primary or Comprehensive Valve Center when the likelihood of a durable repair exceeds 95% and expected mortality is below 1%. |
| Progressive LV enlargement or falling LVEF on serial studies | 2b | ACC/AHA 2020: surgery may be considered. |
Summary of guideline positions [2, 3]; decisions rest with the Heart Team and depend on repairability, operative risk and patient preference.
In secondary MR, intervention is considered only for MR that persists after optimised medical therapy. The 2025 ESC/EACTS guideline recommends transcatheter edge-to-edge repair for selected symptomatic patients with ventricular secondary MR and LVEF < 50% who meet specific clinical and echocardiographic criteria [2].
Surveillance Intervals
| Severity | Echo interval |
|---|---|
| Mild | Every 3–5 years |
| Moderate | Every 1–2 years |
| Severe | Every 6–12 months; more often if the LV is dilating |
ACC/AHA 2020, asymptomatic patients with normal LV function [3]. Earlier review with new symptoms, new AF, or a change in LV size or function.
Frequently Asked Questions
Can a small colour jet represent severe MR?
Yes. An eccentric jet that adheres to the atrial wall loses momentum and looks smaller than a central jet of the same volume, and in acute MR a high LA pressure shortens the jet. The flow convergence zone, vena contracta, pulmonary vein flow and quantitative measures carry more weight than jet area.
Is an EROA of 0.30 cm² severe?
Not on its own. The severe thresholds are the same in primary and secondary MR, and 0.30–0.39 cm² is moderate–severe. It is graded severe when at least three specific criteria for severe MR are also present, or when an elliptical orifice or low flow explains the lower value in secondary MR.
Why can PISA mislead?
It assumes a hemispheric convergence zone, a single frame that represents the whole of systole, and an accurately measured radius, which is squared. Elliptical orifices, wall constraint, non-holosystolic jets and multiple jets each violate one of these assumptions.
When is CMR helpful in MR?
When echocardiographic measures disagree or image quality is limited, and when accurate LV volumes would change management. CMR derives regurgitant volume from stroke volume and aortic flow, independent of jet shape.
Related Pages
References
- Zoghbi WA, Adams D, Bonow RO, et al. Recommendations for Noninvasive Evaluation of Native Valvular Regurgitation: A Report from the American Society of Echocardiography. J Am Soc Echocardiogr. 2017;30(4):303–371. doi:10.1016/j.echo.2017.01.007
- Praz F, Borger MA, Lanz J, et al. 2025 ESC/EACTS Guidelines for the management of valvular heart disease. Eur Heart J. 2025;46(44):4635–4736. doi:10.1093/eurheartj/ehaf194
- Otto CM, Nishimura RA, Bonow RO, et al. 2020 ACC/AHA Guideline for the Management of Patients With Valvular Heart Disease. Circulation. 2021;143(5):e72–e227. doi:10.1161/CIR.0000000000000923
- Lancellotti P, Pibarot P, Chambers J, et al. Multi-modality imaging assessment of native valvular regurgitation: an EACVI and ESC council of valvular heart disease position paper. Eur Heart J Cardiovasc Imaging. 2022;23(5):e171–e232. doi:10.1093/ehjci/jeab253
- Robinson S, Ring L, Augustine DX, et al. The assessment of mitral valve disease: a guideline from the British Society of Echocardiography. Echo Res Pract. 2021;8(1):G87–G136. doi:10.1530/ERP-20-0034
- Stone GW, Lindenfeld J, Abraham WT, et al. Transcatheter Mitral-Valve Repair in Patients with Heart Failure. N Engl J Med. 2018;379(24):2307–2318. doi:10.1056/NEJMoa1806640
- Asch FM, Grayburn PA, Siegel RJ, et al. Echocardiographic Outcomes After Transcatheter Leaflet Approximation in Patients With Secondary Mitral Regurgitation: The COAPT Trial. J Am Coll Cardiol. 2019;74(24):2969–2979. doi:10.1016/j.jacc.2019.09.017
- Topilsky Y, Michelena H, Bichara V, et al. Mitral valve prolapse with mid-late systolic mitral regurgitation: pitfalls of evaluation and clinical outcome compared with holosystolic regurgitation. Circulation. 2012;125(13):1643–1651. doi:10.1161/CIRCULATIONAHA.111.055111
- Adamo M, Massussi M, Ajmone Marsan N, et al. 2025 ESC/EACTS valvular heart disease guidelines: practical updates on mitral and tricuspid regurgitation. Eur Heart J Suppl. 2026;28(Suppl 4):iv83–iv96. doi:10.1093/eurheartjsupp/suag001