BACKGROUND: In cases of pure mitral stenosis, it is known that the impairment of left ventricular(LV) ejection performance is frequently accompanied, but long term follow up studies on the LV ejection performance after successful percutaneous mitral valvuloplasty are rare on far. METHODS: An prospective investigation was performed on 32 casas of patients, 10 being male and 22 female, who have beem maintained after successful precutaneous mitral valvuloplasty of pure mitral stenosis. The LV ejection preformances have been measured with cardiomechanography and echocardiography before and following the procedure, and the follow-up periods were 24 months in average, in the range of 12 to 35 months. RESULTS: The stroke volume, cardiac output, cardiac index, ejection fraction, mean velocity of circumferential shortening and fractional shortening(FS), which are indices of LV ejection perfomance, all increased in follow-up than before procedure. In addition, LV end-diastolic dimension and LV end-diastolic dimension index, which are indicis of LV preload, increased, and the end-systolic LV wall stress which is an index of afterload, decreased. And the ratio measured FS to expected FS, which in an index of myocardial contractility, increased in follow-up. CONCLUSION: The successful percutaneous mitral valvuloplasty of pure mitral stenosis is found to improve LV ejection performance in long term by increasing preload, decreasing afterload, and increasing myocardial contractility of left venrticle.