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.
- Rheumatic heart disease (rare)
- Malignant Carcinoid
- 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.
- 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.
|Valve area||>1.0||1- 0.5||<0.5|
|Peak gradient (mm Hg)||<10-25||25-40||>40|