The valve area derived from the Gorlin formula has been used clinically for decades as an index of severity on the assessiment of valve stenosis, in spite of some limitations on Gorlin formula studied in aortic stenosis and mitral bioprostheses. It had been shown that Gorlin valve area varied if the hemodynamic conditions during measurement are changed. Valve resistance has been proposed as an alternative hemodynamic indicator, but initially this index was not used because it was unlikely to remain constant at different flow rates. Recently valve resistance provided a better indices of hemodynamic obstruction than mitral valve area, and these stenotic indices usually estimated by angiographic method and we studied the valve resistance by Doppler echocardiographic measurement.

To compare the clinical implication about these stenotic indices measured by echcoardiography and cardiac catheterization, we studied 41 patients of mitral stenosis with normal sinus rhythm. The results were as follows ; 1) In catheterization, increased heart rate, mean pressure gradient and decreased diastolic time was observed, but mitral area, resistance, cardiac output and mitral flow was not different. 2) Linear regression analysis showed negative correlation of mitral valve resistance and Gorlin mitral area(echocardiography r=-0.84, catheterization r=-0.84)(p<0.001). 3) Correlation coefficeint of mitral valve area and mitral valve resistance between echocardiography(r=0.87) and catheterization(r=0.82) showed positive correlation(p<0.001).

These results suggest that mitral valve resistance by echocardiography is a useful method in the evaluation of the severity of mitral stenosis.