Most commonly a consequence of Rheumatic fever and is rare. May coexist with mtiral stenosis.
Rheumatic thickening may be more subtle than of the mitral leaflets so more challenging to identify.
Other rarer causes include:
- Carcinoid syndrome
- Ebstein’s anomaly
- ‘Functional’ tricuspid stenosis as a result of obstruction of the valve by a large RA tumour, thrombus or vegetation.
Assessment:
2D imaging as normal to assess the structure of the valve:
- Normal, rheumatic or myxomatous?
- Ebstein’s?
- Are all the valve leaflets normal? Does thickening affect tips or body of leaflets?
- Leaflet calcification? Focal or diffuse?
- Leaflet mobility normal or reduced? How reduced?
- Any doming or prolapse of the leaflets?
- Any evidence of papillary muscle rupture?
- Any tricuspid valve vegetation sor abscesses?
- Annulus normal, dilated or calcified? Normal annulus in adults has diameter of 28+/- 5mm in A4C. Significant dilation indicated by diastolic annular diameter >35mm (>21mm/m^2 indexed).
Colour:
Look for coexistent tricuspid regurgitation.
CW/PW:
Record forward flow with CW in A4C.
If in AF need to average over at least 5 cardiac cycles.
Trace the VTI of the tricuspid inflow – measures mean pressure gradient in mmHg.
Mean gradient is the most common method of assessing severity.
Estimation of valve area from pressure half time is not well validated for tricuspid stenosis and not necessarily advised.
If you wish, measure downward E slow for TV inflow:
Severe also indicated by PHT >190