Drug-induced long-QT syndrome and torsade de pointes: an underrated problem?

This editorial refers to ‘Epidemiology of symptomatic drug-induced long QT syndrome and torsade de pointes in Germany’ by G. Sarganas et al ., on page 101. Drugs that cause an acquired disorder of myocardial repolarization with a characteristic prolongation of the QT interval on electrocardiogram (ECG) are numerous and widely used for a variety of cardiac and non-cardiac indications. This exposes many patients, who are on these medications, to the risk of a lethal form of polymorphic ventricular tachycardia known as torsades de pointes (TdP). Indeed, one of the most frequent causes of restrictive drug labelling or withdrawal has been prolongation of the QTc interval associated with fatal cardiac arrhythmias.1 While our increasing understanding of the molecular and cellular changes that are induced by drugs that produce this phenomenon, and our ability to acquire and analyse huge quantities of electrocardiographic data have complemented our clinical observations,2 it has been noted that the incidence of drug-induced TdP remains difficult to estimate and may, in fact, be much higher than the literature suggests.3In this issue of the Journal , Sarganas et al .4 have posited that this underestimation of the incidence of drug-induced long-QT syndrome (diLQTS) and TdP may be the result of under-reporting. They attempted to address the problem using active surveillance. In this study, between 2008 and 2011, patients were actively screened at 51 Berlin-area hospitals for diLQTS/TdP using …