Objective. To identify early echocardiographic abnormalities at the time of diagnosis of polymyositis (PM) and dermatomyositis (DM) and follow the echocardiographic findings during the first 3 months of therapy. Methods. We included 30 PM/DM patients (23/7) with a mean age of 42.3 +/- 1.6 years and without cardiovascular symptoms. Age-matched healthy patients served as controls. Clinical characteristics were recorded. Traditional echocardiography and tissue Doppler imaging (TDI) were performed to measure systolic [ejection fraction, right ventricular fractional area change (RV FAC), lateral and tricuspid annulus s velocities] and diastolic echocardiographic variables (mitral inflow velocities: E, A; deceleration time: DT; lateral and tricuspid annulus e', a' velocities, lateral E/e'). Results. The left and right ventricular systolic dysfunction detected by TDI at the time of the PM/DM diagnosis improved, and characteristic values at the end of the followup period were comparable to those of the controls (lateral s: 10.6 +/- 0.2, 8.7 +/- 0.4, 9.6 +/- 0.3, 11.3 +/- 0.2 cm/s; RV FAC: 45.2 +/- 2.3, 36.9 +/- 1.5, 42.2 +/- 1.3, 46.9 +/- 1.2%; tricuspid s: 13.3 +/- 0.2, 9.5 +/- 0.4, 10.3 +/- 0.3, 11.6 +/- 0.5 cm/s; control, 0, 1, and 3 mos, respectively). Measurements indicated the development of diastolic dysfunction at 3 mos (E/A: 1.4 +/- 0.1, 1.29 +/- 0.05, 1.03 +/- 0.05, 0.92 +/- 0.05; DT: 148.6 +/- 3.6, 157.3 +/- 5.7, 168.3 +/- 6.0, 184.3 +/- 6.2 ms; lateral e': 12.8 +/- 0.3, 12.1 +/- 0.5, 10.2 +/- 0.6, 10.8 +/- 0.8 cm/s; E/e': 5.6 +/- 0.1, 5.0 +/- 0.22, 6.92 +/- 0.46, 7.64 +/- 0.47; control, 0, 1, and 3 mos, respectively). Conclusion. TDI is a useful method to detect early cardiac abnormalities complementing the conventional echocardiographic measurements. LV and RV systolic dysfunction found in the acute phase significantly improved during the first 3 months of therapy; however, deterioration of diastolic dysfunction was also observed.