QT interval prolongation, torsade de pointes and renal disease

Abstract

Torsade de pointes is a form of polymorphic ventricular tachycardia occurring in a setting of prolonged QT interval on surface electrocardiogram. Several non-antiarrhythmic drugs including antibiotic and antipsychotic agents have been shown to prolong cardiac repolarization predisposing to torsade de pointes ventricular tachycardia. Blockade of the delayed rectifier (repolarising) potassium current and drug interactions with inhibitors of the cytochromes P450 (CYP)-mediated metabolism are the most common underlying mechanisms. Many antiarrhythmic drugs have been also implicated in prolonging QT interval and triggering torsades de pointes, especially during chronic therapy or in case of acute high dose toxicity. Progressive renal disease is associated from the earliest stages with increased QT interval and dispersal and with an increased risk of cardiovascular death, specifically sudden death. It has also been reported that cCorrected QT (QTc) interval prolongation and torsade de pointes are associated with end-stage renal disease (ESRD) and that they can be a cause of sudden death in ESRD. We present a case of torsade de pointes in a 82-year-old Italian woman with chronic renal failure.