]> 2026-07-31T12:14:33+00:00 WBR0795 0 en Metoprolol Metoprolol doesn't affect the QT interval. It does not increase the risk for torsades de pointes. Lidocaine Lidocaine doesn't affect the QT interval. It does not increase the risk for torsades de pointes. Propafenone Propafenone doesn't affect the QT interval. It does not increase the risk for torsades de pointes. Dofetilide Dofetilide is a Class III antiarrhythmic used for cardoversion. It prolongs the QT interval and leads to torsades de pointes. Mexiletine Mexiletine doesn't affect the QT interval. It does not increase the risk for torsades de pointes. Torsades de pointes is a ventricular tachycardia characterized by polymorphic wave forms with typical crescendo-decrescendo pattern about the isoelectric line. Torsades de pointes is a complication of prolonged QT interval that can progress to ventricular fibrillation and sudden death. Many medications can lead to torsades de pointes, but the classical drugs associated with QT prolongation include Class IA and Class III antiarrhythmics (except amiodarone). Dofetilide is a class III antiarrhythmic used in the treatment of atrial fibrillation for the restoration of regular rhythm. It is a complication that can be seen in up to 10% of patients in certain studies often indicating the need for hospitalization and close monitoring of patients receiving this agent.<br/> '''Educational Objective:''' Torsades de pointes is a complication of medications that increase the QT interval such as Class IA and Class III antiarrhythmics namely dofetilide.<br/> '''References:''' Viskin S. Long QT syndromes and torsade de pointes. The Lancet. 1999;354(9190):1625-1633. Pharmacology D Cardiology 2020-10-28T01:43:58Z 2459150.5721991 WBR0795