SHM Converge Scientific Abstract ePoster Gallery-Done With Methadone

Pdf Summary

This case describes a 35-year-old woman with polysubstance use disorder who presented after recurrent syncopal episodes preceded by dyspnea. She had recently relapsed to heroin use while taking high-dose methadone (160 mg/day). On admission, she was tachycardic, with mild hypokalemia (K 3.2 mmol/L) and an electrocardiogram showing a markedly prolonged QTc of 636 ms. Cardiac monitoring captured torsades de pointes, which was followed by syncope.<br /><br />She was treated with potassium and magnesium repletion and admitted to the ICU for close monitoring. Despite initial correction, she had another episode of torsades de pointes during hospitalization. Methadone was then discontinued, and serial ECGs showed gradual improvement in the QT interval. After stabilization, she was discharged on naltrexone for opioid dependence.<br /><br />The discussion emphasizes that methadone can prolong the QT interval by blocking cardiac potassium channels involved in ventricular repolarization, increasing the risk of torsades de pointes and potentially fatal ventricular fibrillation. Risk is higher in the presence of hypokalemia, hypomagnesemia, congenital long QT syndrome, structural heart disease, or other QT-prolonging medications. The case highlights the importance of obtaining a baseline ECG before starting methadone and repeating ECG monitoring regularly, especially in high-risk patients. Alternative treatments should be considered for patients with prolonged QT or elevated arrhythmia risk.

Asset Subtitle

Mutaz Alkalbani

Meta Tag

Author List Mutaz Alkalbani, Sami Tahhan

Category Clinical Vignettes

Concept Methadone

Concept QT Interval

Concept Prolonged QT Interval

Concept Torsades de Pointes

Concept Ventricular Repolarization

Distinguished Non-Finalist

Presenter Organization Eastern Virginia Medical School

Presenting Author Mutaz Alkalbani

Track Adult

Keywords

methadone

torsades de pointes

QT prolongation

syncope

polysubstance use disorder

hypokalemia

electrocardiogram

ventricular arrhythmia

magnesium repletion

naltrexone

Methadone

QT Interval

Prolonged QT Interval

Torsades de Pointes

Ventricular Repolarization