Assessment of Tricuspid and Pulmonary Orifice Areas
Due to the rarity of tricuspid stenosis and pulmonary stenosis, no general agreement exists on what constitutes critical orifice area in these cases. Generally a gradient of 5mmHg causes venous hypertension. In the case of pulmonary stenosis, gradients of < 50mmHg are well tolerated.
Gradients of >100mmHg require intervention. Gradients between 50-100mmHg merit correction depending on the case.
Alternatives to Gorlin Formula
Hakki et al proposed a simplified formula for calculation of valve orifice area and had found good correlation. This formula may not be useful in substantial tachycardia.
Assessment of Valvular Regurgitation
The severity of valvular regurgitation is generally graded by visual assessment, although calculation of the regurgitant fraction is used occasionally.
Visual Assessment of Regurgitation
Valvular regurgitation may be assessed visually by determining the relative amount of radiographic contrast medium that opacifies the chamber proximal to its injection.