Clinical Factors Associated With Ventricular Dysrhythmia in Emergency Department Patients With Severe QTc Prolongation After Drug Overdose

Clinical Factors Associated With Ventricular Dysrhythmia in Emergency Department Patients With Severe QTc Prolongation After Drug Overdose

Michael D. Simpson et al.
 Academic Emergency Medicine, June 10, 2025

šŸ©ŗ Clinical Takeaways:

  • QTc ā‰„ 500 ms alone does not predict dysrhythmia.

  • Focus on physiologic instability:

    • Bradycardia

    • Acid-base status

    • Hemodynamic compromise

  • If none of the above are present, risk of ventricular dysrhythmia is very low ā€” may support conservative monitoring.

  • Patients with any of the three markers warrant heightened observation, telemetry, and possibly ICU-level care.

šŸ“Š Study Design:

  • Retrospective analysis of 1,265 patients (from 2,764 screened) in the Toxicology Investigators Consortium Registry (2013ā€“2023).

  • Included patients: age ā‰„13, acute/acute-on-chronic overdose, QTc ā‰„500 ms on ED ECG.

  • Primary outcome: Ventricular dysrhythmia.

  • Secondary outcomes: Death, cardiac arrest, need for rhythm control, ECMO.

āš ļø Key Risk Factors for Ventricular Dysrhythmia:

(All significant in multivariable regression)

  • Bradycardia (aOR 3.12; 95% CI 1.35ā€“6.90)

  • Acidosis (aOR 3.02; 95% CI 1.42ā€“6.23)

  • Shock (aOR 4.54; 95% CI 2.07ā€“9.75)

šŸŸ¢ Absence of all three:

  • Negative predictive value = 98.2% (95% CI 97.2ā€“98.9%) for dysrhythmia.

Simpson, M.D., Tang, K.B., Donnino, M.W., Chai, P.R., Culbreth, R., Campleman, S., Wax, P., Manini, A.F., Burns, M.M. and Toxicology Investigators Consortium, 2025. Clinical Factors Associated With Ventricular Dysrhythmia in Emergency Department Patients With Severe QTc Prolongation After Drug Overdose. Academic Emergency Medicine.

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