In addition to clinical findings, the determination of LVEF or, more recently, the use of biomarkers, are the most commonly used methods to diagnose and assess cardiotoxicity. Regarding the identification of biomarkers, troponin I and N-terminal fragment of pro-brain natriuretic peptide (NT-proBNP) are the most commonly used and investigated in the context of clinical studies. The advantages of using biomarkers include their minimally invasive identification, which is less expensive than echocardiography, and, unlike radionuclide ventriculography, they avoid irradiation of the patient. Furthermore, the interpretation of their results does not depend on the observer's experience, thus avoiding interobserver variability. Several studies have shown the role of troponins as indicators of early anthracycline-induced cardiotoxicity or other chemotherapeutic agents, which are able to predict impaired ventricular function and higher incidence of cardiac events in patients with elevated values of this marker compared with patients with normal troponin values. Regarding the use of brain natriuretic peptides such as NT-proBNP, several studies have shown a correlation between persistently high values of this biomarker and impaired heart function parameters, in particular LVEF.