Retrospective evaluation of electrocardiographic and echocardiographic predictors of doxorubicin-induced cardiotoxicity

Aim: By evaluating repolarization parameters in electrocardiography (ECG) recordings of patients receiving doxorubicin-containing chemotherapy (CT) with diagnosis of lymphoma, we aimed to detect subclinical cardiac toxicity that may develop during CT in the early period. Methods: Patients who applied to the outpatient clinic of Karadeniz Technical University, Faculty of Medicine, Department of Cardiology between 2022 and 2024, received doxorubicin-containing CT with a diagnosis of lymphoma, and had ECG and ECHO records in the outpatient clinic were included in the study by retrospective screening from the hospital automation system. Repolarization parameters such as QT dispersion (QTd), corrected QTd (QTcd), Tp-e interval, Tp-e/QT, Tp-e/corrected QT (QTc), JT interval and corrected JT (JTc) interval were calculated in ECG recordings before and after 2 cycles of CT. Cardiac biomarkers, left ventricular ejection fraction (LVEF) and global longitidunal strain (GLS) were also evaluated before and after treatment. Results: The mean age of the 36 patients included in the study was 54 ± 16.05 years, 50% were male and 50% were female. Prolongation of repolarization parameters was detected in ECG recordings obtained before, after 2nd, 4th and 6th cycles of CT (p<0.001). Although no significant change was observed in LVEF before and after treatment (p=0.286), a decrease in GLS was detected (p<0.001). Cardiac biomarkers were also increased supporting cardiotoxicity (p<0.001). When the change in ECG repolarization parameters between CT cycles was examined, statistically significant changes were detected in JTc after 2nd cycle CT, QTd and QTcd after 4th cycle CT, and Tp-e/QT and Tpe/QTc after 6th cycle CT (p<0.001). Conclusion: Changes in ECG repolarization parameters may occur during doxorubicin-containing CT. Our study showed that repolarization parameters calculated by ECG can be used to detect doxorubicin-induced cardiotoxicity in the subclinical stage. Therefore, in our study, it was concluded that the use of repolarisation parameters evaluated by ECG in the detection of doxorubicin-induced cardiac damage not only before CT but also at all stages of follow-up may be useful. Keywords: Lymphoma, doxorubicin, cardiotoxicity, ECG repolarization parameters