TNNI3 and breast cancer: Therefore, this study was conducted to determine the prevalence of anthracycline-induced cardiotoxicity in breast cancer patients admitted to the oncology unit, Teaching Hospital, Karapitiya, Sri Lanka based on electrocardiography (ECG) findings and cardiac biomarkers including cardiac troponin I (cTnI) and N terminal pro-brain natriuretic peptide (NT-pro BNP) since these parameters provide early identification of acute changes in the heart although the echocardiography requires some extent of damage to the heart for the diagnosis of cardiotoxicity [16].