Background: Isolated T wave inversion in asymptomatic adults is known to be a normal variant, however, the structure and function of myocardium in these patients have not been evaluated although these patients are common in clinical situation. We want to investigate the myocardial change in these patients using the speckle tracking image to detect the subtle change of myocardium comparing with normal volunteers. Methods: The twenty-seven women among the forty two patients were available to accept the accurate echocardiographic datas (mean age: 54.0짹12.3 years). All the patients were ruled out for coronary artery disease by exercise stress test, SPECT or coronary angiography. We measured the conventional echocardiographic parameters and analyzed the datas using the speckle tracking image (ex. strain, strain rate, rotation, rotation rate and time to peak torsion) at 16 segments in parasternal short axis view. Age-matched twenty-five normal volunteers were also analyzed. Results: The patients with isolated T inversion had lower E velocity (64.1짹11.3 vs. 76.5짹14.6 cm/sec, p=0.021), E prime (5.46짹1.63 vs. 7.12짹1.85 cm/sec, p=0.031) and circumferential strain (-20.97짹3.42 vs. -23.12짹3.06, p=0.048) compared with normal volunteers. Our datas showed increased time interval to apical peak systolic rotation rate (418짹51 vs. 453짹76ms, p=0.043) in these patients. Other parameters were not significantly different between two groups. Lower E prime and E velocity were significantly correlated with the presence of isolated T inversion after controlling for age, LV mass and LV dimension. (Beta=-0.265, p=0.016) Conclusion: Our study showed the patients with isolated T inversion had decreased velocity of LV relaxation, decreased circumferential systolic function and the decrease of apical systolic synchronicity. This result suggests these patients have the myocardial early dysfunction although they don���t have overt heart disease or coronary artery disease. These patients may not be normal variant and more evaluation about the myocardial change and prognosis will be needed.