Droperidol use in the ED is associated with which serious rhythm disturbance due to QT prolongation?

• A. Hypotension
• B. Seizures
• C. QT prolongation leading to torsades de pointes
• D. Hyperkalemia

Answer: (C)

QT prolongation from droperidol can trigger torsades de pointes, a life-threatening polymorphic ventricular tachycardia. Droperidol can block cardiac potassium channels that help repolarize the heart, lengthening the QT interval. When the QT is prolonged, early afterdepolarizations can initiate torsades, which may degenerate into more dangerous rhythms or cause sudden death if not treated promptly. In the ED, this is why clinicians monitor the QT interval and electrolytes, avoid combining multiple QT-prolonging drugs, and be prepared to treat torsades with magnesium sulfate and electrolyte correction while stopping the offending medication. Hypotension, seizures, or hyperkalemia are not the rhythm disturbance specifically linked to QT prolongation from this drug.