This study was undertaken to analyze the diagnostic value of Doppler echocardiographic determination of pressure gradient and valve orifice area for the evaluation of balloon valvuloplasty in mitral stenosis as well as the echocardiographic assessment of calcification, leaflet motion and the subvalvular apparatus for characterization of the most favorable morphologic prerequisites for this procedure. Doppler echocardiographic studies were performed in 24 patients with mitral stenosis, 21 women and three men, age range from 29 to 79 years, mean age 55 years, one day before and after balloon valvuloplasty and the results were compared with invasively-determined hemodynamic measurements. The Doppler echocardiographic determination of the mean pressure gradient before and after balloon valvuloplasty was carried out with the modified Bernoulli equation from the velocity profile of the stenotic jet and calculation of the mitral valve orifice area using the pressure half-time method. Echocardiographic assessment of valve morphology and motion was based on two-dimensional echocardiographic cross-sectional images. Calcification, as observed in the parasternal cross-sectional image, was classified as absent (grade 0), slight to moderate (grade 1) or severe (grade 2). Motion of the valve leaflets, as judged from the apical four- and two-chamber views, was assigned one of five grades taking into consideration the motion of the bodies of both leaflets from the systolic baseline position as less than 10 degrees, between 10 and 45 degrees and more than 45 degrees. The subvalvular apparatus, that is the chordae and the papillary muscles, were graded as unremarkable (grade 0), slightly altered (grade 1) and markedly altered (grade 2). Using a score derived by adding the grade of these three criteria, a formal value between 0 and 8 was calculated. Hemodynamic measurements were carried out with standard techniques employing simultaneous registrations of left atrial and left ventricular pressure for evaluation of the mean diastolic pressure gradient. Determination of the stroke volume was based on biplane left ventriculograms using Simpson's rule. The valve orifice area was calculated according to the Gorlin formula. Dilatation was carried out with a Bifoil (12F, balloon diameter 2 X 19 mm) or Trefoil (10F, 3 X 12 mm) valvuloplasty catheter. After PTVP, on comparison of the Doppler-echocardiographically determined pressure gradient (5.7 +/- 1.9 mm Hg) with that determined invasively (6.4 +/- 3.2 mm Hg) there was a moderate correlation (n = 19, r = 0.74, SEE = 1.3 mm Hg) where the noninvasively-determined values, in general, were smaller.(ABSTRACT TRUNCATED AT 400 WORDS)