What cardiac risk is associated with droperidol when used in the ED?

• A. QT prolongation
• B. Tachycardia
• C. Hypotension
• D. Seizures

Answer: (A)

Droperidol’s main cardiac risk is QT interval prolongation. It blocks the cardiac potassium channels that are responsible for repolarization, which lengthens the time the ventricles take to reset between beats. This prolonged repolarization can progress to torsades de pointes, a dangerous form of polymorphic ventricular tachycardia. The risk is higher with higher doses and when there are electrolyte disturbances (low potassium or magnesium), bradycardia, congenital long QT, or other drugs that extend the QT interval. While other effects like tachycardia, hypotension, or rare seizures can occur, the specific cardiac danger most associated with droperidol is QT prolongation leading to potential torsades de pointes.