The authors investigated by echocardiography changes of left ventricular function in 79 patients with non-Hodgkin lymphoma or Hodgkin's disease who were treated by chemotherapy containing doxorubicin. In 22% patients they diagnosed during treatment a significant gradual decline of the left ventricular ejection fraction (change > 10% or a drop of EF below 50%) after a cumulative dose of 185 +/- 52 mg/m2 doxorubicin (median 200 mg/m2). Changes of the ejection fraction were at the expense of an increasing endsystolic left ventricular volume. These changes correlated closely with the increase of endsystolic stress of the left ventricular wall (r = -0.87). After administration of a cumulative doxorubicin dose of 100 mg/m2 a significant deterioration of indicators of diastolic filling of the left ventricle occurred--of the isovolumic relaxation period (IRP) and deceleration time (DT). The contribution of these early changes of diastolic function of the left ventricle for assessment of the risk of development of systolic dysfunction is not unequivocal. Prolongation of IRP > 12% as compared with the baseline value and at the same time above 95 ms had a 50% sensitivity, 50% specificity, a 26% positive prediction value a 74% negative prediction value and 50% diagnostic accuracy, change of DT > 13%, and at the same time prolongation above 200 ms had a 47% sensitivity 55% specificity, a 22% positive prediction value, a 78% negative prediction value and a 53% diagnostic accuracy. The authors found a significant relationship between the assessed changes of left ventricular function and clinical and haemodynamic indicators. Only the patients' age correlated significantly with IRP and DT values. Changes of the left ventricular ejection fraction were not associated with clinical signs of cardiac failure, they did not call for cardiological intervention and did not affect the course of chemotherapy. Contrary to some statements in the literature, the authors did not consider the described functional changes as sufficient to justify interference with chemotherapy. On the other hand, their importance for the development of late sequelae of chemotherapy with anthracyclines in adult patients must be based on long-term prospective follow-up.