Percutaneous mitral valvuloplasty (PMV) was successfully performed in 112 (95%) out of 118 patients (32 M, 80 F, mean age: 38 +/- 11 years) with mitral stenosis. There was a significant increase in the mitral valve area (MVA) from 0.9 +/- 0.2 to 2.0 +/- 0.7 cm2 p less than 0.0001, a decrease in the mean mitral gradient from 17 +/- 6 to 6 +/- 3 mmHg, p less than 0.001, and a rise in cardiac output from 4.3 +/- 0.8 to 4.8 +/- 1.2 L/min, p less than 0.001. The morphologic features of the mitral stenosis was evaluated using echocardiographic score. Patients with a low-score (less than or equal to 8) had more effective dilation of mitral stenosis compared to patients with a high-score over 8 (0.9 to 2.2 vs 0.8 to 1.6 cm2, p less than 0.001), despite the similar EBDA/BSA (effective balloon dilating area/body surface area). The patients with good results after PMV (MVA greater than or equal to 1.5 cm2) were more likely to be in normal sinus rhythm (p less than 0.0001), younger age (p less than 0.001), smaller left atrial size (p less than 0.05), and lower total echoscore (p less than 0.002), especially in leaflet mobility (p less than 0.02) and degree of calcification (p less than 0.002), compared to patients with relatively poor result after PMV (MVA less than 1.5 cm2). There were no differences in EBDA/BSA, calcification on fluoroscopy, and history of previous surgical commissurotomy between the 2 groups. Mitral regurgitation (MR) developed or increased in severity in 41 (37%) cases.(ABSTRACT TRUNCATED AT 250 WORDS)