The initial 85 patients who successfully underwent percutaneous mitral valvuloplasty (PMV) with the Inoue balloon catheter at the Guangdong Cardiovascular Institute between November 1985 and November 1988 had a mean follow-up period of 5 +/- 1 year (range 43 to 79 months). Before and after PMV and at follow-up, mean diastolic mitral gradients by the catheter method were 17.5 +/- 6.2, 3.1 +/- 3.3 and 3.3 +/- 3.4 mm Hg, respectively (p < 0.001 before vs after PMV and before vs follow-up; and p > 0.05 after PMV vs follow-up). Mean diastolic mitral gradients by the Doppler method were 18 +/- 6, 8 +/- 5 and 9 +/- 5 mm Hg, respectively (p < 0.001 before vs after PMV and before vs follow-up; and p > 0.05 after PMV vs follow-up). Mean diastolic mitral gradients by the Doppler method were 18 +/- 6, 8 +/- 5 and 9 +/- 5 mm Hg, respectively (p < 0.001 before vs after PMV and before vs follow-up; and p > 0.05 after PMV vs follow-up). Mitral valve areas by the echo-Doppler method were 1.1 +/- 0.3, 2.0 +/- 0.4 and 1.8 +/- 0.5 cm2, respectively (p < 0.001 before vs after PMV and before vs follow-up; and p > 0.05 after PMV vs follow-up). Phonocardiographic and vectorcardiographic studies, and cardiopulmonary exercise testing showed significant improvement after PMV and at follow-up.(ABSTRACT TRUNCATED AT 250 WORDS)