QT monitoring in chemotherapy.

This review provides a comprehensive overview of cardiac electrophysiology principles as they apply to oncology care, with a focus on QT interval assessment and monitoring. Accurate measurement of the QT interval and appropriate heart rate correction-particularly using the tangent method and Fridericia formula-are essential for evaluating arrhythmic risk in cancer patients, who are especially vulnerable due to the cardiotoxic potential of many chemotherapeutic agents. We highlight key risk factors for QT prolongation, including electrolyte imbalances, underlying cardiac conditions, and concurrent use of QT-prolonging medications. Current cardiac monitoring protocols during chemotherapy are examined, with specific reference to clinical practices at The University of Texas MD Anderson Cancer Center. These practices underscore the importance of structured surveillance and timely intervention. Effective management requires a multi-pronged approach involving standardized measurement techniques, proactive risk stratification, and patient education. Counseling patients on symptoms such as palpitations, dizziness, or syncope facilitates early detection and evaluation. Given the expanding list of QT-prolonging agents, clinicians are encouraged to use resources like Torsades.org for up-to-date drug information. In the absence of formal guidelines for certain agents, institution-specific protocols defining thresholds for treatment initiation, dose adjustment, and monitoring frequency are critical for ensuring consistency, safety, and evidence-based decision-making in cardio-oncology.