21. Prolonged QT Intervals in Patients with Out-of-Hospital Ventricular Tachycardia Cardiac Arrest

Objective: To determine the prevalence and outcome of out-of-hospital ventricular tachycardia (VT) cardiac arrest with a prolonged QT interval and to identify the subset with torsades de pointes (TdP).Methods: Design: Retrospective review. Setting: Fire department-based paramedic system. Participants: Non-traumatic VT cardiac arrest (1/91-12/94) with a supraventricular perfusing rhythm (SVPR) and a measurable QT interval. Interventions: QT interval was measured from a SVPR and corrected QT interval (QTc) was calculated (prolonged if ≥0.45 sec). VT was classified as polymorphic or monomorphic.Results: 190 patients met inclusion criteria. 51% of patients had a prolonged QTc (PQTc). The overall hospital discharge rate was 28.4%. No difference with respect to paramedic-witnessed arrests in each QTc group was found (25.8% normal QTc [NQTc] vs. 27.8% PQTc; p = 0.752). Patients with PQTc were less likely to be discharged from the hospital (19.6% vs. 37.6%; p = 0.01). Patients with PQTc were not more likely to have PVT (37% vs. 40%; p = 0.705). 16 (8.4%) patients had TdP. 27.8% of TdP and 26.8% of non-TdP patients were discharged (p = 0.912).

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Prolonged QTc: "Mind the Gap"

Bangladesh Critical Care Journal ◽

10.3329/bccj.v2i1.19970 ◽

2014 ◽

Vol 2 (1) ◽

pp. 44-45

Author(s):

Ahmad Mursel Anam ◽

Raihan Rabbani ◽

Farzana Shumy ◽

M Mufizul Islam Polash ◽

M Motiul Islam ◽

...

Keyword(s):

Cardiac Arrest ◽

Long Qt Syndrome ◽

Qt Interval ◽

Torsades De Pointes ◽

Junior Doctors ◽

Long Qt ◽

Acquired Long Qt Syndrome ◽

Prolonged Qt Interval ◽

Prolonged Qt ◽

Qt Syndrome

We report a case of drug induced torsades de pointes, following acquired long QT syndrome. The patient got admitted for shock with acute abdomen. The initial prolonged QT-interval was missed, and a torsadogenic drug was introduced post-operatively. Patient developed torsades de pointes followed by cardiac arrest. She was managed well and discharged without complications. The clinical manifestations of long QT syndromes, syncope or cardiac arrest, result from torsades de pointes. As syncope or cardiac arrest have more common differential diagnoses, even the symptomatic long QT syndrome are commonly missed or misdiagnosed. In acquired long QT syndrome with no prior suggestive feature, it is not impossible to miss the prolonged QT-interval on the ECG tracing. We share our experience so that the clinicians, especially the junior doctors, will be more alert on checking the QT-interval even in asymptomatic patients. DOI: http://dx.doi.org/10.3329/bccj.v2i1.19970 Bangladesh Crit Care J March 2014; 2 (1): 44-45

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Cardiac Arrest Associated with Combination Cisapride and Itraconazole Therapy

Journal of Cardiovascular Pharmacology and Therapeutics ◽

10.1177/107424849600100309 ◽

1996 ◽

Vol 1 (3) ◽

pp. 255-258 ◽

Cited By ~ 3

Author(s):

Craig A. Hoover ◽

J. Kevin Carmichael ◽

Paul E. Nolan ◽

Frank I. Marcus

Keyword(s):

Cardiac Arrest ◽

Qt Interval ◽

Cardiac Death ◽

Torsades De Pointes ◽

Pertinent Literature ◽

Elevate Serum ◽

Normal Limits ◽

Prokinetic Drug ◽

Prolonged Qt Interval ◽

Prolonged Qt

We report a case of cardiac arrest associated with cisapride in combination with itraconazole and provide a brief review of pertinent literature. Cisapride (Propulsid; Janssen Pharmaceuticals, Titusville, NJ), a gastrointestinal prokinetic drug, has recently been reported to prolong the QT interval. Itraconazole, an oral antifungal agent, is an inhibitor of cytochrome P450 (CYP3A4) metabolism and may elevate serum drug levels of compounds metabolized by this pathway. A 31-year-old woman had a witnessed cardiac arrest while taking the combination of cisapride and itraconazole. Following resucitation, the prolonged QT interval returned to normal after withdrawal of both agents. Echocardiography and cardiac catheterization were within normal limits; electrophysiologic testing failed to induce ventricular tachycardia/ventricular fibrillation. She has had no documented arrhythmias since the arrest. This combination can now be added to a growing list of drugs that may cause torsades de pointes and sudden cardiac death.

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Bedside monitoring of the QT interval

American Journal of Critical Care ◽

10.4037/ajcc1998.7.3.183 ◽

1998 ◽

Vol 7 (3) ◽

pp. 183-189 ◽

Cited By ~ 7

Author(s):

LK Rimmer

Keyword(s):

Ventricular Tachycardia ◽

Qt Interval ◽

Warning Signs ◽

Cardiac Repolarization ◽

Qt Intervals ◽

Increased Risk ◽

Prolonged Qt Interval ◽

Clinical Interest ◽

Prolonged Qt ◽

Available Information

Cardiac repolarization, represented on the ECG by the QT interval, is of particular clinical interest in critical care. Once it is measured and corrected for changes in heart rate, the QT interval is known as the QTc. Measurement of the QT interval is important because a prolonged QT interval is associated with ventricular tachycardia and sudden cardiac death. Despite the serious complications associated with a prolonged QT interval, the interval is not routinely measured because a standardized method for measuring it has not been established and the length of QT interval critical to the development of ventricular tachycardia has not been determined. Much has been written about the conditions associated with prolonged QT intervals and specific actions to take when complications appear. Guidelines to be used for QT analysis in the clinical area, based on currently available information, include (1) procedures for measuring QT interval and calculating QTc, (2) procedures for QT analysis, (3) warning signs that indicate increased risk of ventricular tachycardia associated with a prolonged QT interval, and (4) actions to consider once increased risk is determined.

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Retrospective diagnosis of prolonged QT interval and Torsades de Pointes made by analysis of ICD electrograms

Journal of Electrocardiology ◽

10.1016/j.jelectrocard.2004.04.006 ◽

2004 ◽

Vol 37 (3) ◽

pp. 237-239 ◽

Cited By ~ 1

Author(s):

Frank Bogun ◽

Subramaniam C Krishnan

Keyword(s):

Qt Interval ◽

Torsades De Pointes ◽

Retrospective Diagnosis ◽

Prolonged Qt Interval ◽

Prolonged Qt

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Postoperative Nausea and Vomiting in Patients with Prolonged QTc

10.1093/med/9780199764495.003.0070 ◽

2013 ◽

Author(s):

Shilpa Rao ◽

Jerrold Lerman

Keyword(s):

Postoperative Nausea ◽

Qt Interval ◽

Postoperative Nausea And Vomiting ◽

Torsades De Pointes ◽

Nausea And Vomiting ◽

Receptor Antagonists ◽

Prolonged Qt Interval ◽

Prolonged Qt ◽

Type 3 ◽

Potential Interactions

A panoply of pharmacological and nonpharmacological strategies are currently employed to attenuate the risk of postoperative nausea and vomiting (PONV) in children, including 5-hydroxytryptamine type 3 (5-HT3) receptor antagonists. 5-HT3 receptor antagonists can prolong the QT interval, which can be a precursor of torsades de pointes (TdP), particularly in children with congenital or acquired prolonged QT interval. This chapter summarizes the causes of prolonged QT interval, the potential interactions of prolonged QT interval with antiemetics and anesthetics, and strategies to prevent PONV.

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