Mitral regurgitation vena contracta
MR VC · Zoomed PLAX (and apical 4-chamber for biplane), narrow sector, Nyquist 50–70 cm/s, measured at the jet neck
Normal range & thresholds
Primary (degenerative) MR[4,7]:
Secondary (ventricular) MR: the 2025 ESC/EACTS guidelines associate EROA ≥30 mm² and/or regurgitant volume ≥45 mL with adverse outcome — lower numbers than for primary MR, because the same leak in a dilated, failing ventricle carries a worse prognosis. Quantify in a euvolaemic, normotensive state.[6]
Supporting signs of severe MR: systolic flow reversal in a pulmonary vein, a dense triangular CW jet, mitral E >1.2 m/s with an E-dominant inflow, and a flail leaflet or a large coaptation defect.
| Mild | Moderate | Severe | |
|---|---|---|---|
| Vena contracta width | <0.3 cm | 0.3–0.69 cm | ≥0.7 cm |
| 3D vena contracta area | <0.4 cm² | ≥0.4 cm² | |
| EROA (PISA) | <0.20 cm² | 0.20–0.39 | ≥0.40 cm²[59] |
| Regurgitant volume | <30 mL | 30–59 mL | ≥60 mL |
| Regurgitant fraction | <30% | 30–49% | ≥50% |
Supporting signs of severe MR: systolic flow reversal in a pulmonary vein, a dense triangular CW jet, mitral E >1.2 m/s with an E-dominant inflow, and a flail leaflet or a large coaptation defect.
Pathophysiology
As for aortic regurgitation, the vena contracta is the narrowest neck of the jet and approximates the effective regurgitant orifice, relatively independently of driving pressure and machine settings. The critical distinction in mitral disease is not measurement but mechanism: in primary MR the valve is diseased and the ventricle is a victim, so fixing the valve fixes the problem; in secondary MR the valve is normal and the ventricle or the atrium has pulled it apart, so the leak is a marker of the disease as much as a cause — which is why the treatment pathway, the severity thresholds and the evidence base all differ.[4,6,64,91]
Raised by
- Primary: myxomatous degeneration with prolapse or flail (chordal rupture), rheumatic disease, endocarditis with perforation, papillary muscle rupture after infarction, cleft leaflet, radiation, drug-induced valvulopathy, systemic lupus/antiphospholipid
- Secondary, ventricular: ischaemic and non-ischaemic dilated cardiomyopathy — annular dilatation, leaflet tethering and apical papillary displacement
- Secondary, atrial: long-standing atrial fibrillation and HFpEF with a dilated annulus and a normal ventricle — a category the 2025 ESC/EACTS guidelines define explicitly (LVEF ≥50%, no regional wall motion abnormality, LVEDD <56 mm in women / <63 mm in men, annular anteroposterior diameter >35 mm, LAVI >34 mL/m²)[6]
- Dynamic: systolic anterior motion in HCM, ischaemia-induced MR that appears only on exertion
- Prosthetic and post-TEER residual or recurrent regurgitation
Lowered by
- Successful repair, replacement or transcatheter edge-to-edge repair
- Falsely small: an eccentric jet in the wrong plane, inadequate zoom, hypotension or general anaesthesia (secondary MR can halve under anaesthesia — a notorious source of intraoperative under-grading)
- Reduction in secondary MR with effective GDMT and reverse remodelling — a genuine improvement, and the reason severity should be re-assessed on optimal therapy before intervening
Technique & pitfalls
- Zoom, narrow sector, high frame rate. As for AR, this is a millimetre measurement.
- Measure at the neck of the jet, just distal to the flow convergence, perpendicular to the jet.
- The mitral orifice is frequently non-circular, especially in secondary MR where it is a crescentic slit along the coaptation line — a single PLAX width then under-represents it. Use a biplane measurement (PLAX plus apical) or, better, 3D vena contracta area.[4]
- PISA-derived EROA assumes a hemispherical convergence and a circular orifice; it underestimates in secondary MR and overestimates with eccentric jets. Correct for the angle in a non-planar leaflet geometry.
- Grade secondary MR only when the patient is euvolaemic, normotensive and on optimal GDMT — the 2025 guideline is explicit, and this changes intervention decisions.[6]
- Multiple jets are not additive by width; go volumetric or 3D. Volumetric quantification was calibrated against angiography and remains the reference when colour methods conflict.[78]
Pseudo-change & artefact
- Loading conditions — the dominant confounder in secondary MR. Blood pressure, volume status, sedation and anaesthesia can move the grade by a whole category in either direction.
- Inadequate zoom, wide sector, low frame rate, Nyquist and gain settings.
- Eccentric and wall-hugging jets — under-graded by colour area, and their vena contracta must be sought in the correct plane.
- Non-circular orifices measured in a single plane — systematic underestimation in secondary MR.
- PISA angle and hemisphere assumptions.
- Prosthetic valves and post-TEER states: shadowing and multiple orifices make all standard methods unreliable — use TOE, 3D, and volumetric methods.[20]
- A late-systolic-only jet (mitral valve prolapse) over-graded by peak measurements — report the regurgitant volume, not the peak orifice.
Treatment thresholds
- Symptomatic severe primary MR → mitral valve surgery, class I, with repair strongly preferred to replacement in suitable anatomy at an experienced centre.[6,7]
- Asymptomatic severe primary MR → surgery for LVEF ≤60% or LVESD ≥40 mm (class I); the 2025 ESC/EACTS guidelines add LVESDi ≥20 mm/m² — a change that identifies the smaller patient whose absolute dimension never reaches 40 mm.[6,7]
- Also class IIa in asymptomatic severe primary MR with new atrial fibrillation, systolic pulmonary artery pressure >50 mmHg, or LAVI ≥60 mL/m² in sinus rhythm — and with a high likelihood of durable repair at a Heart Valve Centre.[6,7]
- Symptomatic high-risk primary MR unsuitable for surgery → TEER, upgraded to class IIa in 2025.[6]
- Severe ventricular secondary MR with persistent symptoms on optimal GDMT and COAPT-like anatomy → TEER, class I, level A in the 2025 ESC/EACTS guidelines.[6,64]
- Atrial secondary MR → surgery class IIa and transcatheter therapy class IIb for symptomatic patients despite optimal therapy, with atrial fibrillation ablation and appendage occlusion considered.[6]
Next step
- Next: complete the multiparametric grading — biplane or 3D vena contracta, PISA EROA, regurgitant volume and fraction, pulmonary vein flow. Never grade on colour jet area.[4]
- Then: define primary versus secondary and, if secondary, ventricular versus atrial — this determines the entire pathway.[6]
- Then: optimise GDMT and re-assess before intervening in secondary MR; measure LV dimensions indexed to BSA, LVEF, GLS, LAVI, and pulmonary pressures.
- Then: TOE with 3D for mechanism and repairability[35] (Carpentier classification, leaflet segments, calcification, annular dimensions); CMR regurgitant fraction where echo is equivocal.
- Then: Heart Team at a Heart Valve Centre — the likelihood of durable repair is itself a guideline criterion, and it depends on the centre.
Drugs
- Primary MR: no medical therapy alters the natural history. Treat hypertension; treat heart failure if the ventricle has failed — but do not use medical therapy as an alternative to surgery in a patient who meets an operative threshold.[7]
- Secondary MR: GDMT is the treatment — ARNI, beta-blockers, MRAs and SGLT2 inhibitors reduce MR severity by reverse remodelling, and CRT reduces it in dyssynchrony. Severity must be re-assessed after optimisation.[6,11,12,64]
- Atrial secondary MR: rhythm control, rate control and decongestion; treat the atrial cardiomyopathy.[6]
- Dynamic MR from systolic anterior motion: beta-blockers, disopyramide, and mavacamten — the MR resolves when the obstruction is relieved.[13,72]
- Diuretics and nitrates reduce the regurgitant volume acutely by reducing preload and afterload.
Reversibility
Primary MR: abolished mechanically and immediately by repair. LV end-diastolic dimension falls rapidly, within days to weeks, as the volume load disappears; end-systolic dimension falls far less, and a pre-operative LVESD ≥40–45 mm or LVEF ≤60% predicts persistent post-operative dysfunction — the volume was reversible, the contractile injury was not.[91,92]
Secondary MR: genuinely reversible with medical therapy. Optimised GDMT and CRT reduce MR severity in a substantial proportion by reversing the ventricular remodelling that caused it — which is exactly why the guidelines insist on re-assessment on optimal therapy before intervention. After TEER, the leak is reduced immediately, and COAPT showed that in the right anatomy this translates into fewer hospitalisations and lower mortality.[6,64]
Atrial secondary MR improves with restoration of sinus rhythm and decongestion, incompletely once the annulus is permanently dilated.[6]
Secondary MR: genuinely reversible with medical therapy. Optimised GDMT and CRT reduce MR severity in a substantial proportion by reversing the ventricular remodelling that caused it — which is exactly why the guidelines insist on re-assessment on optimal therapy before intervention. After TEER, the leak is reduced immediately, and COAPT showed that in the right anatomy this translates into fewer hospitalisations and lower mortality.[6,64]
Atrial secondary MR improves with restoration of sinus rhythm and decongestion, incompletely once the annulus is permanently dilated.[6]