Torsade de pointes, QT interval prolongation 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 [1,2]. Several non-antiarrhythmic drugs [3–5] have been shown to prolong cardiac repolarization predisposing to torsade de pointes ventricular tachycardia. Blockade of the delayed rectifier (repolarising) potassium current and drug interactionswith inhibitors of the cytochromes P450 (CYP)-mediated metabolism are the most common underlying mechanisms [6,7]. 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 [8]. Progressive renal disease is associated with an increased risk of cardiovascular death, specifically sudden death [9]. It has been reported that Corrected QT 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 [10,11]. Moreover it has also been reported that left ventricular mass is increased from the earliest stages of renal disease (near normal renal function), the predominant pattern being eccentric left ventricular hypertrophy (LVH) and that LVH is linked to increased QT interval and dispersal, and with minor rhythm abnormalities, providing a link with the high risk of sudden death in this population too [9]. Furthermore electrolyte disturbances, bradycardia, female sex, advanced age, underlying heart disease have been reported as other risk factors predisposing to torsade de pointes [12–15]. We present a case of torsade de pointes in a 72-year-old Italian woman with chronic renal failure. A 72-year-old Italian woman was admitted to the Emergency Department. A history of chronic renal failure, a history of hypertension, a history of previous acute myocardial infarction and stroke were present. A history of recent hypotension was present too. Blood pressure values were 90/50 mm Hg, the oxygen saturation was 95% on room air. The patient was in treatment also with sotalol, with