From Wikiecho
Pulmonary stenosis occurs when there is obstruction to the outflow from the right ventricle This results in the reduction of flow of blood to the lungs. In 80% of the cases, the obstruction is at the pulmonary valve level.
[edit] Aetiology
- isolated
- as part of other congenital heart defects including Transposition of Great arteries or Tetrology of Fallot
- other syndromes including Noonan's syndrome.
- Rheumatic heart disease (rare)
- Malignant Carcinoid
[edit] 2D echocardiography
- Thickened leaflets with systolic bowing in valvular stenosis.
- Difficult to distinguish between valvular, sub valvular and supra valvular stenosis with 2D echocardiography.
- Post stenotic pulmonary artery dilatation can be visualised sometimes.
[edit] Doppler echocardiography
- Ante grade velocity increased with corresponding maximum and mean pressure gradients.
- Pulmonary valve area can be calculated using the continuity equation.
- Pulmonary Valve Area = (Cross sectional areaRVOT * VTIRVOT)/ VTIPV
- The site of obstruction can be difficult to diagnose by 2D echo. Cautious use of colour flow mapping and PW Doppler can pin point the location of obstruction.
[edit] Severity Assessment
Severity of pulmonic stenosis
| Severity | mild | moderate | severe
|
| Valve area | >1.0 | 1- 0.5 | <0.5
|
| Peak gradient (mm Hg) | <10-25 | 25-40 | >40
|