Sleep-Associated Torsades de Pointes: A Case Report

Abstract

Torsades de Pointes (TdP) is a polymorphic ventricular tachycardia that occurs in the presence of an acquired or congenital long QT syndrome (LQTS). We present the case of a 57 year-old man with end-stage renal disease on methadone maintenance in which there occurred multiple episodes of TdP during sleep. The patient was found to have a QTc interval of 548 milliseconds, and the dysrhythmia was successfully treated with isoproterenol infusion and methadone substitution. It is surmised that the patient had a multifactorial, acquired LQTS that during somnolence, reached a critical threshold of QT prolongation to lead to the development of TdP.

Torsades De Pointes in a 71-Year-Old Female With Normal Qt Interval After Azithromycin Use

“…Though drug-induced TdP resulting in cardiac arrest is rare, it is potentially disastrous even in hospital settings due to the propensity of transitioning into ventricular fibrillation [1][2]. In the inpatient setting, clinicians must keep in mind that administration of medications with a propensity to prolong the QT interval is more likely to precipitate TdP compared to administration of the medication in the outpatient setting since hospitalized patients often have multiple risk factors which can provoke a new arrhythmia [1][2][3][4][5]. Although the prevalence of TdP is unknown in the 400,000 sudden cardiac deaths in the United States per year, torsades is estimated to account for less than five percent [5].…”

“…A reason for the proarrhythmic state of many hospitalized patients is that patients are often older, with underlying cardiac, renal, or hepatic dysfunction, and are receiving medications intravenously, resulting in a rapid response from the heart [1][2][3][4][5]. Prior to initiating therapies with a propensity to prolong the QT interval, it is crucial to obtain a baseline electrocardiogram to evaluate the QT interval.…”

“…Torsades de pointes (TdP) is defined as a polymorphic ventricular tachycardia characterized by a pattern of twisting of the points, which occurs when there is dysfunction in the repolarization of cardiac myocytes due to either a congenital or acquired prolonged QT interval [1][2][3][4][5]. QT prolongation with subsequent ventricular fibrillation was initially reported in response to quinidine in 1964 by Slezer and Wray [3].…”