Anatomy
The pulmonary valve is a tricuspid, semilunar valve that is similar in construction and size to the aortic valve. The valve has a right (R) -, a left (L) and an anterior cusp (A). The pulmonary valve has a slightly more left, anterior and superior position to the aortic valve.
Regurgitation
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. |
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Causes of pulmonary regurgitation
| Physiologic | Congenital | Acquired |
|---|---|---|
| PR is found in 40-80% of people | incorrectly constructed valve cusp(s) | As a result of pulmonary hypertension. |
| Absence or partial absense of a valve cusp | By balloon dilatation of the PV in correction of pulmonary stenosis | |
| Carcinoid | ||
| Endocarditis |
Stenosis
Pulmonary stenosis is very rare.
Quantification of pulmonary stenosis
| Parameter | Mild | Moderate | Severe |
|---|---|---|---|
| PGmax (mmHg) | < 36 | 36 - 64 | > 64 |
| Vmax (m/s) | < 3 | 3 - 4 | > 4 |
Causes of pulmonary stenosis
| Congenital | Acquired |
|---|---|
| Tetralogy van Fallot | Rheumatic fever |
| Tumor |
References
European Heart Journal - Cardiovascular Imaging (2022) 23, e171–e232
European Journal of Echocardiography (2010) 11, 223?244 J Am Soc Echocardiogr. 2009 Jan;22(1):1-23