ECG with QTc measurement
An electrocardiogram (ECG) records the heart’s electrical activity. A QTc measurement is especially relevant because a prolonged QT interval can increase concern for dangerous rhythm disturbances. The FDA’s discussion of QT prolongation and abnormal rhythms illustrates why a QT-focused review matters when substances or medications may affect cardiac conduction.
A normal tracing does not settle every question. Cardiac symptoms, personal and family cardiac history, medication exposure, electrolyte status, and the setting’s monitoring capability still matter. An abnormal ECG or QTc needs clinician review rather than a do-it-yourself conclusion.