Cancer Therapy-Related Cardiac Dysfunction
Baseline risk, surveillance, and intervention thresholds.
Mechanisms of Cardiotoxicity
Anthracyclines cause Type I cardiotoxicity through topoisomerase-2β-mediated DNA damage and mitochondrial oxidative stress in cardiomyocytes, producing dose-dependent, cumulative, and often irreversible myocyte injury. HER2-targeted agents such as trastuzumab cause Type II cardiotoxicity by blocking neuregulin-1/ErbB2 survival signaling that cardiomyocytes rely on for stress adaptation, resulting in reversible dysfunction that is generally not dose-dependent. These distinct mechanisms explain why anthracycline injury tends to be permanent and cumulative-dose-related, while trastuzumab-related dysfunction often recovers with drug interruption and guideline-directed therapy, and why combining both agents markedly increases cardiotoxic risk.