Erythromycin induced Torsades de Pointes: case report and review of the literature.

We report a case of an 82 year old woman with bilateral pneumonia who developed repeated episodes of polymorphic ventricular tachycardia with QT prolongation (Torsades de Pointes) after intravenous infusion of erythromycin. After discontinuation of erythromycin, the QT interval returned to normal and there was no recurrence of this arrhythmia. The association of intravenous erythromycin and this potentially fatal ventricular arrhythmia has been described in 15 similar cases reported in the literature. Both in vitro and in vivo studies have shown that erythromycin exerts electrophysiologic effects on the cardiac muscle similar to that of class IA antiarrhythmic drugs and that cross sensitivity may exist between this class of drugs and erythromycin. The definition, pathophysiology, etiology, clinical and electrocardiographic feature, and prevention and treatment of "Torsades de Pointes" are described in this article.