Amiodarone-induced sudden onset of polymorphic ventricular tachycardia following dislodgement of a temporary pacemaker: a case report

Abstract

Amiodarone is commonly used to instantly reverse potentially fatal myocardial arrhythmias, but may also potentiate arrhythmic adverse effects, such as QT prolongation and torsades de pointes. This case describes a 56-year-old male patient who, after experiencing a myocardial infarction, had undergone temporary pacemaker (TPM) insertion for bradycardia-induced ventricular tachycardia (VT); however, his VT persisted post-insertion and intravenous amiodarone was administered. Within a few minutes, monomorphic VT occurred, which progressed to polymorphic VT arrest (i.e. torsades de pointes). The polymorphic VT induced by amiodarone resolved on withdrawal of amiodarone and a subsequent switch to lignocaine. In view of suspected TPM dislodgement, a new TPM was inserted and paced at a higher rate. The patient did not show further ventricular arrhythmia and, prior to discharge, had a permanent pacemaker implanted and was hemodynamically stable.