In this study we analyzed a group of 219 lymphoma patients treated with chemotherapy cycles containing doxorubicine. We that found that in 118 patients who were analyzed retrospectively the strongest risk factor for cardiovascular events that increases the risk of cardiotoxicity is hypertension. In the group of 101 patients who were analyzed prospectively we found early symptoms of heart failure on echocardiography in 55 (55%) of patients treated with first-line chemotherapy cycles containing doxorubicin. Moreover a higher incidence of independent systolic dysfunction (30%) and independent diastolic dysfunction (20%) was found than both of these forms occurring concurrently (5%). During an observation period of 5 years, in a comparative analysis of both groups, 20 cardiac deaths (11 sudden cardiac deaths and 9 deaths secondary to progressive heart failure) occurred in the retrospective group compared to a lack of cardiac deaths in the prospective group. Performing echocardiography and diagnosing systolic or diastolic dysfunction before treatment and after the 3 treatment cycle allowed the implementation of primary cardioprotection in the form of liposomal doxorubicin use in further cycles. There was no difference in treatment efficacy (complete remission – CR) in patients with DLBCL treated with conventional (CR 77.5%) and liposomal (CR 90%) forms of doxorubicin.