Cardiotoxicity is a serious side effect of doxorubicin and requires vigilant monitoring. Pediatric oncologists typically use echocardiograms and electrocardiograms (ECGs) to assess heart function before, during, and after treatment. If signs of cardiac damage are detected, the dose of doxorubicin may be adjusted, or alternative therapies may be considered. Additionally, medications such as dexrazoxane may be used to protect the heart.