QT Prolongation
Definition
A delay in the electrical repolarization of the heart's ventricles, visible on an ECG as a lengthened QT interval. Drug-induced QT prolongation increases the risk of a dangerous heart rhythm called torsades de pointes, which can lead to sudden cardiac death.
Example
Azithromycin, certain antipsychotics, and some antiemetics can prolong the QT interval. Combining two QT-prolonging drugs significantly increases cardiac risk.
Related Terms
Mentioned in Guides
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Major Drug Interactions Everyone Should KnowA practical guide to the most clinically significant drug-drug interactions — including serotonin syndrome and QT prolongation — that every …
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Understanding QT ProlongationQT prolongation is a potentially life-threatening cardiac side effect caused by dozens of commonly prescribed medications. This guide explains what …