Aortic Regurgitation: Severity Criteria by Vena Contracta, PHT, and Aortic Reversal
According to ASE guidelines and Pandian N.G. et al. (2023) on echocardiographic assessment of rheumatic heart disease, grading the severity of aortic regurgitation (AR) requires the integration of several groups of parameters. Relying solely on one indicator is unacceptable.
Groups of Parameters for Assessing AR Severity
Qualitative indices: density of the CWD jet spectrum, flow reversal in the descending aorta, flow convergence zone, pressure half-time of regurgitation (PHT) by CWD.
Semi-quantitative indices: vena contracta (VC) width, ratio of regurgitant jet width to LVOT width.
Quantitative Doppler measurements: regurgitant volume, regurgitant fraction, EROA.
Supporting data: size and function of the LV.
Criteria for Severe AR
| Parameter | Threshold for Severe AR |
|---|---|
| Density of CWD jet spectrum | Dense spectrum |
| PHT (CWD) | <200 ms |
| Vena contracta (VC) width | >0.6 cm |
| Jet width / LVOT width | ≥65% |
| Regurgitant volume | ≥60 ml |
| Regurgitant fraction | ≥50% |
| EROA | ≥0.3 cm² |
| Flow reversal in the descending aorta | Present |
| LV size | LV dilation |
These threshold values are presented in identical wording in the ASE scientific statement (2023) and in the recommendations by Pandian N.G. et al. (2023).
Special Clinical Situations
In the context of congenital defects (Manual of Echocardiography for Congenital Heart Diseases, 2024), a peak gradient >50 mmHg and increased age at diagnosis are risk factors for developing significant AR. A peak gradient <50 mmHg combined with moderate/severe AR or LV dysfunction associated with obstruction requires separate interpretation. [clarify] — the complete list of echocardiographic signs of severe AR in this source is not fully provided.
Frequently asked questions
What PHT value indicates severe AR?
PHT by CWD <200 ms indicates severe aortic regurgitation (ASE, 2023; Pandian N.G. et al., 2023).
What vena contracta width corresponds to severe AR?
A vena contracta width >0.6 cm is a criterion for severe AR.
What quantitative thresholds define severe AR?
Regurgitant volume ≥60 ml, regurgitant fraction ≥50%, and EROA ≥0.3 cm².
What does flow reversal in the descending aorta mean?
Flow reversal in the descending aorta and LV dilation are present in severe AR and are considered qualitative and supporting signs, respectively.
Can AR be graded by a single parameter?
No. Integration of qualitative, semi-quantitative, quantitative indices, and supporting data on the LV is necessary.