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
|Colour flow PR jet width 𝛼
|Small, usually <10mm in length with a narrow origin
|Large, with a wide origin; may be brief in duration
|Reversal flow in pulmonary artery branches
|CW signal of PR jet 𝛽
|Dense/steep deceleration, early termination od diastolic flow
|Pulmonic vs aortic flow by PW
|Normal or slightly increased
|VC width (mm)
|Deceleration time of PR (ms)
|Pressure half-time (ms) 𝛾
|Jet width/annulus ratio (%)
|PR index 𝛿
|R Vol (mL)
|RV size 𝜀
|Normal or 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.