Trileaflet valve – anterior left and right leaflets.
Can be challenging to see – but assess in:
- PLAX RV outflow view.
- PSAX at aortic valve level.
- Subcostal short axis view.
Attempt to visualise main pulmonary artery beyond the valve to bifurcation into left and right pulmonary arteries.
Can be affected by:
- Rheumatic processes
- Carcinoid heart disease.
- Trauma.
- Infective endocarditis.
- Myxomatous degeneration.
- Congenital dysplasia.
If any pulmonary valve disease is present need to careful identify any associated features – pul regurgitation, coexistant tricuspid disease, RV failure/RVOT obstruction and pulmonary artery dilation (common in pulm stenosis).
Assessment:
Visual assessment for:
- Tricuspid/bicuspid or dysplastic.
- Any thickening or calcification? Diffuse or focal?
- Cusp mobility normal or reduced?
- Doming of cusps?
- Any evidence of infundibular or supravalvular stenosis? Any MPA/branch pulm arteries?
- Vegetations?
- Thrombus visible in MPA?
Colour:
Assess for coexistent regurgitation.
CW:
CW doppler trace through leaflet to give Vmax and VTI (trace).
Can either use PLAX RV outflow view or PSAX (whichever gives greatest value).
Simplified Bernoulli equation will give a peak gradient.
If peak velocity in RVOT is >1m/s (measured with PW) use the full Bernoulli equation for greater accuracy.
where V2 is the peak transpulmonary velocity assessed with CW and V1 is peak RVOT velocity assessed by PW.
PW:
Can be used to determine exactly where velocity is greatest – e.g. infundibular/supravalvular stenosis.
Also used as above to identify RVOT peak velocity of >1m/s.
Severity:
Determined by peak gradient.
Some texts suggest >40mmHg is severe. These are the BSE values which will need to be used for the exam.
- Mild – <3m/s
- Moderate – 3-4m/s
- Severe >4m/s
Some texts suggest >40mmHg is severe. These are the BSE values which will need to be used for the exam.
Probably worth considering lower values as significant in clinical practice given normal studies are ~5mmHg.