Torsade de pointes following intravenous haloperidol administration in a patient with complete heart block.

Torsade de pointes (TdP) due to QT prolongation is often a drug-induced ventricular tachyarrhythmia. Different classes of drugs including antiarrhythmics, antipsychotics, and antimicrobials may lead to TdP by a patient-specific response altering repolarization. Combinations of other TdP risk factors such as bradycardia, ischemia, or electrolyte abnormalities are usually also present. In this paper, we describe the development of TdP after the administration of intravenous haloperidol in a patient with complete heart block. The importance of evaluating predisposing risk factors before the administration of any potential QT-prolonging medications is highlighted.