Prevention of Torsade de Pointes in Hospital Settings

Abstract

Cardiac arrest due to torsade de pointes (TdP) in the acquired form of drug-induced long-QT syndrome (LQTS) is a rare but potentially catastrophic event in hospital settings. Administration of a QT-prolonging drug to a hospitalized population may be more likely to cause TdP than administration of the same drug to an outpatient population, because hospitalized patients often have other risk factors for a proarrhythmic response. For example, hospitalized patients are often elderly people with underlying heart disease who may also have renal or hepatic dysfunction, electrolyte abnormalities, or bradycardia and to whom drugs may be administered rapidly via the intravenous route.In hospital units where patients' electrocardiograms (ECGs) are monitored continuously, the possibility of TdP may be anticipated by the detection of an increasing QT interval and other premonitory ECG signs of impending arrhythmia. If these ECG harbingers of TdP are recognized, it then becomes possible to discontinue the culprit drug and manage concomitant provocative conditions (eg, hypokalemia, bradyarrhythmias) to reduce the occurrence of cardiac arrest.The purpose of this scientific statement is to raise awareness among those who care for patients in hospital units about the risk, ECG monitoring, and management of drug-induced LQTS. Topics reviewed include the ECG characteristics of TdP and signs of impending arrhythmia, cellular mechanisms of acquired LQTS and current thinking about genetic susceptibility, drugs and drug combinations most likely to cause TdP, risk factors and exacerbating conditions, methods to monitor QT intervals in hospital settings, and immediate management of marked QT prolongation and TdP. Characteristic Pattern of TdPThe term torsade de pointes was coined by Dessertenne in 1966 as a polymorphic ventricular tachycardia characterized by a pattern of twisting points. 1 Several ECG features are characteristic of TdP and are illustrated in Figure 1. First, a change in the amplitude and morphology (twisting) of the QRS complexes around the isoelectric line is a typical feature of the arrhythmia;The American Heart Association and the American College of Cardiology Foundation make every effort to avoid any actual or potential conflicts of interest that may arise as a result of an outside relationship or a personal, professional, or business interest of a member of the writing panel. Specifically, all members of the writing group are required to complete and submit a Disclosure Questionnaire showing all such relationships that might be perceived as real or potential conflicts of interest. The American Heart Association requests that this document be cited as follows: Drew BJ, Ackerman MJ, Funk M, Gibler WB, Kligfield P, Menon V, Philippides GJ, Roden DM, Zareba W; on behalf of the American Heart Association Acute Cardiac Care Committee of the Council on Clinical Cardiology, the Council on Cardiovascular Nursing, and the American College of Cardiology Foundation. Prevention of torsade de pointes in hospital settings: a sc...

Electrocardiographic Findings in Systemic Lupus Erythematosus: Data From an International Inception Cohort

“…This could contribute to the null effect of our study. Since the threshold at which QTc duration should be considered abnormal also has been a matter of debate for many years (34,35), we used different cutoffs in our analysis, from 440 msec to 500 msec.…”

Propofol-associated QTc prolongation

“…The independent (i.e. predictor) variables included baseline QTc interval (QTc 1 ), serum albumin concentration, age, sex, weight, Charlson-Deyo comorbidity index (a validated measure of case-mix severity based on comorbid conditions) and the use of any QTc interval-prolonging medications [Drew et al 2004[Drew et al , 2010Yap and Camm, 2003;Viskin et al 2003;Charlson et al 1987Charlson et al , 1994. The QTcprolonging medications evaluated were those available through the hospital formulary and available for use in the local ICU and are listed in Table 1.…”

“…Prolongation of the QTc interval is associated with increasing risk for fatal ventricular arrhythmias; therefore, ECG monitoring is recommended if there is a risk of QTc prolongation [Bazett, 1997;Fridericia, 2003;Drew et al 2010;Yap and Camm, 2003]. The risk of QTc prolongation is greater in the ICU for multiple reasons, including acute or unstable disease, the potential for electrolyte imbalances, and possible exposure to QTc prolonging medications [Drew et al 2004;Viskin et al 2003;Beitland et al 2014].…”

“…The risk of QTc prolongation is greater in the ICU for multiple reasons, including acute or unstable disease, the potential for electrolyte imbalances, and possible exposure to QTc prolonging medications [Drew et al 2004;Viskin et al 2003;Beitland et al 2014]. Medications known to increase the risk of QTc interval prolongation and arrhythmia risk include antiarrhythmic agents, antipsychotics, tricyclic antidepressants, fluoroquinolones, macrolides and azole antifungals [Drew et al 2010;Yap and Camm, 2003;Viskin et al 2003;Beitland et al 2014]. While the potential for QTc prolongation may be known for numerous medications, assessment of QTc interval changes for medications has only been required since 2005 [Darpo, 2010].…”

2014 ESC/ESA Guidelines on Non-cardiac Surgery: Cardiovascular Assessment and Management

“…Management with magnesium sulphate should be considered for patients with TdP and long QT syndrome. 192 Beta-blockade, combined with temporary pacing, is suggested in patients with TdP and sinus bradycardia. Isoproterenol is recommended in patients with recurrent, pause-dependent TdP, who do not have congenital long QT syndrome.…”