Figure 4. Examples of two patients who underwent radionuclide ventriculography to measure left ventricular ejection fraction (LVEF) before and after anthracycline chemotherapy. The upper left image shows the baseline LVEF of the first patient, which was 71% (normal) and then decreased to 50% after the end of chemotherapy and start of trastuzumab therapy (upper right). The lower left image shows the baseline LVEF (52%) of a patient with breast cancer before the start of chemotherapy, which decreased to 46% during follow-up (lower right), leading to the use of cardioprotective medication. The images were kindly provided by Dr. Márcia Modesto (Nuclear Medicine Department of the Instituto Brasileiro de Controle do Câncer, São Paulo, Brazil).