cardiotoxic

Cardiotoxic refers to substances or conditions that damage the heart. It can involve drugs, chemicals, radiation, and certain diseases. Cardiotoxic effects may target the myocardium, conduction system, vasculature, or pericardium and can present as acute injury, cardiomyopathy, arrhythmia, heart failure, or ischemic-like syndromes.

Mechanisms are diverse: direct injury to cardiac myocytes, impaired contractile function, mitochondrial dysfunction, oxidative stress, disruption of calcium handling, fibrosis, and impaired microvascular function. The risk and pattern depend on the agent, dose, and patient factors such as age and preexisting heart disease.

Common cardiotoxic agents include cancer therapies such as anthracyclines (doxorubicin, daunorubicin) and trastuzumab, as well as other chemotherapies, tyrosine kinase inhibitors, and radiation to the chest. Illicit drugs (cocaine, methamphetamine), excessive alcohol, and certain environmental toxins (arsenic, lead) can also contribute. Onset may be acute, during therapy, or occur months to years after exposure.

Evaluation usually starts with baseline cardiac assessment before exposure and ongoing surveillance. Echocardiography is used to monitor left ventricular ejection fraction and may include strain imaging; biomarkers such as troponin and natriuretic peptides can aid detection. Cardiac MRI provides detailed tissue characterization.

Management focuses on reducing exposure when possible and treating established injury. Strategies include dose modification, cardioprotective agents (e.g., dexrazoxane with anthracyclines), and guideline-directed medical therapy for heart failure or arrhythmias. Prevention emphasizes risk assessment, use of less toxic formulations, and early involvement of cardiology and oncology teams for coordinated care.