Tissue Doppler imaging (TDI) was investigated for its applicability for detecting cardiac function and early cardiotoxicity in breast cancer patients treated with anthracyclines. A total of 40 women (age range 18 to 65 years) were enrolled, who had not received anthracyclines previously and had normal systolic and diastolic cardiac function. All healthy patients in the control group were of the same age. Each patient underwent not only standard echocardiographic measurements (ventricular dimensions and wall thickness, ejection fraction, E-wave deceleration time (DT), E/A ratio), but also specific imagings (E-septum separation, pulmonary venous flow), and in addition the myocardial velocity of many segments of mitral anulus obtained with pulsed wave tissue Doppler imaging were performed during the one year of observation period. Based on the results we found that systolic left ventricular function did not change significantly - neither in the study nor in the control group. Diastolic left ventricular function was impaired in 39 patients (97.5%), and 30 (75%) of these showed clear changes by means of both the traditional E/A ratio and TDI. Diastolic dysfunction in 9 patients (22.5%), however, could be detected only with TDI. The analysis of myocardial velocity in different segments showed that diastolic dysfunction does not develop in a homogeneous way but in a different way in segments. Diastolic function was intact in the control group during the study. The detectable myocardial damage occurred in the study group of young female patients without risk factors as a result of one year anthracycline therapy was so severe that the possible outcome might be serious congestive heart failure or death. Our results confirmed our assumptions that TDI is a more precise and useful examination method than traditional ones (E/A ratio or deceleration time) to demonstrate isolated diastolic dysfunction as a result of chemotherapy. Relevant extra information might be given by TDI compared to parameters describing diastolic functions depending on several changing values. TDI may become a regularly and more widely used noninvasive method to detect subclinical cardiotoxicity emerging after chemotherapy.