Aortic regurgitation
Integrated grading, LV size and function for timing, the aorta — and recognising acute severe AR.
Numbers to remember
- Severe: VC >6 mm, jet width/LVOT ≥65%, PHT <200 ms, EROA ≥0.30 cm², RVol ≥60 mL, RF ≥50% [4,34]
- Holodiastolic reversal in the descending aorta with end-diastolic velocity >20 cm/s [4]
- ACC/AHA 2020: surgery if LVEF ≤55%, or LVESD >50 mm / LVESDi >25 mm/m² [7]
Questions echo must answer
Chronic AR is a combined volume and pressure load. The LV dilates and compensates for years before it fails, so serial LV size and function decide timing [7,94]. Quantitative regurgitant volume and EROA predict outcome in asymptomatic patients [95], and GLS adds incremental information [188].
- MechanismCusp disease (bicuspid, prolapse, perforation, rheumatic) versus aortic root dilatation (Carpentier-like classification) [4].
- SeverityIntegrated qualitative, semi-quantitative and quantitative measures [4,34].
- LV consequencesLVEDD, LVESD (indexed), volumes, LVEF, GLS [7,188].
- AortaRoot and ascending aorta, which may be an indication on its own [9].
- Acute?Short PHT, premature mitral closure, small LV, raised LV diastolic pressure: a surgical emergency [4].
Acquisition protocol
- PLAX zoom colourVena contracta at the jet neck; jet width/LVOT ratio [4].
- PSAX-AVCusp morphology, coaptation defect, perforation; jet origin.
- A5C / A3C CWDensity and PHT of the AR envelope [4,43].
- Suprasternal / upper descending aorta PWDiastolic flow reversal; end-diastolic velocity and VTI [4].
- QuantificationRVol = LVOT SV − mitral (or RVOT) SV, or PISA [4].
- LVLVEDD and LVESD (indexed), 3D or biplane volumes, LVEF, GLS [1,188].
- AortaAnnulus, sinuses, STJ and ascending aorta at consistent levels [9,18].
- MitralPremature closure (M-mode) or diastolic MR in acute AR.
- Mechanism and cusp morphology
- VC, jet width ratio
- PHT, CW density
- Descending aortic reversal (EDV)
- RVol, RF, EROA
- LVEDD, LVESD, LVESDi, volumes
- LVEF, GLS
- Aortic dimensions
Diagnosis & severity
| Parameter | Mild | Moderate | Severe |
|---|---|---|---|
| Vena contracta (mm) | <3 | 3–6 | >6 |
| Jet width / LVOT (%) | <25 | 25–64 | ≥65 |
| Pressure half-time (ms) | >500 | 200–500 | <200 |
| Descending aortic reversal | Brief, early | Intermediate | Holodiastolic, EDV >20 cm/s |
| EROA (cm²) | <0.10 | 0.10–0.29 | ≥0.30 |
| RVol (mL) | <30 | 30–59 | ≥60 |
| RF (%) | <30 | 30–49 | ≥50 |
Source: ASE 2017 and EACVI [4,34]. Grade by integrating the measures; no single parameter is enough.
Thresholds that change management
- Symptomatic severe AR → surgery [6,7].
- Asymptomatic severe AR (ACC/AHA 2020) [7]: surgery if LVEF ≤55%; reasonable if LVESD >50 mm or LVESDi >25 mm/m²; may be considered at low surgical risk with progressive decline in LVEF (to 55–60%) or progressive dilatation (LVEDD >65 mm). The 2025 ESC/EACTS guideline uses comparable dimension and EF thresholds [6].
- Aortic dilatation → surgery thresholds for the root or ascending aorta (commonly ≥55 mm, lower in bicuspid valves with risk factors and in genetic syndromes) [6,9].
- Reduced GLS with preserved EF → closer follow-up. Alashi showed incremental prognostic value [188].
- Acute severe AR (endocarditis, dissection, trauma) → emergency surgery [4,136].
Pitfalls & mimics
PitfallEccentric jets hug the anterior mitral leaflet or septum. Jet width underestimates them. Use the VC and quantitative methods [4].
- PHT depends on LV compliance. It shortens in stiff ventricles and with vasodilators, and it is not reliable in chronic compensated AR [4].
- Brief early diastolic reversal in the aorta is normal, especially in older patients. Only holodiastolic reversal counts [4].
- A mild AR jet is common with a bicuspid valve or older age; look for its cause.
- Low blood pressure or tachycardia changes the regurgitant volume. Note BP and heart rate.
- Measure LV size in the same way every time. The indications depend on changes of a few millimetres.