Thirty patients with mitral stenosis were classified into three grades of severity reflected by anterior mitral leaflet and subvalvular apparatus using two-dimensional echocardiography in order to study the possibility of predicting the type of surgery indicated, and were evaluated pre- and postoperatively for systolic and diastolic volumes; left heart function using left ventricular posterior wall movement (LVPWVSmax, LVPWVdmax) and posterior wall excursion (PWE) and newly devised left atrial empty volume ratio (LAEVR). The LVPWVSmax was increased from 57 +/- 7 to 74 +/- 7 mm/s (p less than 0.001) in grade I, from 48 +/- 13 to 63 +/- 9 mm/s (p less than 0.02) in grade II, and from 44 +/- 6 to 64 +/- 7 mm/s (p less than 0.001) in grade III. The LVPWVdmax showed an increase from 68 +/- 15 to 91 +/- 15 mm/s (p less than 0.001) in grade I, from 57 +/- 17 to 86 +/- 18 mm/s (p less than 0.01) in grade II, and from 55 +/- 11 to 83 +/- 6 mm/s (p less than 0.01) in grade III. In the PWE, there was an improvement from 12.4 +/- 1.6 to 15.5 +/- 2.1 mm (p less than 0.01) in grade I; from 10.5 +/- 2.0 to 12.5 +/- 1.5 mm (p less than 0.02) in grade II; and from 9.4 +/- 1.5 to 14.4 +/- 1.5 mm (p less than 0.001) in grade III. In the LAEVR, there was also an improvement from 65 +/- 12 to 39 +/- 21% (p less than 0.01) in grade I.(ABSTRACT TRUNCATED AT 250 WORDS)