Pulmonary regurgitation (PR) is a volume load for the RV. Important regurgitation will lead to RV dilation. Due to this volume load the RV will endure long but eventually will fail.
Quantification of pulmonary regurgitation
Grading the severity of PR |
PR severity classes |
Mild |
Moderate |
Severe |
Qualitative parameters |
Valve morphology |
Normal |
Normal/Abnormal |
Abnormal |
Colour flow PR jet width 𝛼 |
Small, usually <10mm in length with a narrow origin |
Intermediate |
Large, with a wide origin; may be brief in duration |
Reversal flow in pulmonary artery branches |
Absent |
Absent |
Present |
CW signal of PR jet 𝛽 |
Faint/Slow deceleration |
Dense/variable |
Dense/steep deceleration, early termination od diastolic flow |
Pulmonic vs aortic flow by PW |
Normal or slightly increased |
Intermediate |
Greatly increased |
Semi-quantitative parameters |
VC width (mm) |
Not defined |
Not defined |
Not defined |
Deceleration time of PR (ms) |
Not defined |
Not defined |
<260 |
Pressure half-time (ms) 𝛾 |
Not defined |
Not defined |
<100 |
Jet width/annulus ratio (%) |
Not defined |
Not defined |
>65 |
PR index 𝛿 |
Not defined |
Not defined |
<0,77 |
Quantitative parameters |
EROA (mm²) |
Not defined |
Not defined |
Not defined |
R Vol (mL) |
Not defined |
Not defined |
Not defined |
RF (%) |
<20 |
20-40 |
>40 |
Structural parameters |
RV size 𝜀 |
Usually normal |
Normal or dilated |
Usually dilated |
CW, continuous wave; EROA, effective regurgitant orifice area; PR, pulmonic regurgitation; RV right ventricle; PW, pulsed wave; R Vol regurgitant volume; VC, vena contracta.
𝛼 At Nyquist limit of 50-60 cm/s.
𝛽 Steep deceleration is not specific for severe PR
𝛾 Pressure half time is shortened with increasing RV diastolic pressure.
𝛿 PR index ratio of PR duration by CW Doppler to total diastolic time.
𝜀 Unless for other reasons, the RV size is usually normal in patients with mild PR. In acute severe PR, the RV size is often normal. Accepted cut-off values for non-significant RV enlargement (measurements obtained from the apical 4-chamber view): Mid RV dimension ≦33mm, RV end-diastolic area ≦ 28cm², RV end-systolic area ≦16cm². RV fractional area change >32%, maximal.