Podcast 1023: Torsades de pointes

Contributor: Aaron Lessen, MD

Educational Pearls:

• Case review of a patient with recurrent episodes of syncope and shortness of breath, during which she is found to have intermittent runs of polymorphic ventricular tachycardia

• Torsades de pointes is polymorphic ventricular tachycardia occurring in the setting of a prolonged QT/QTc

• Risk of torsades increases substantially when QTc exceeds 500ms

• Causes:

• Common reversible causes include QT-prolonging medications, hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, and structural heart disease

• Congenital causes of a prolonged QT interval are primarily inherited genetic mutations affecting cardiac myocyte ion channels leading to delayed ventricular repolarization

• Treatment:

• Stop any QT-prolonging medications and correct electrolytes

• IV magnesium to suppress recurrent torsades

• Increasing the heart rate with isoproterenol or temporary pacing can prevent the pauses that trigger recurrent episodes

• If the rhythm degenerates into ventricular fibrillation → defibrillate

References

1. Wigginton JG, Agarwal S, Bartos JA, Coute RA, Drennan IR, Haamid A, Kudenchuk PJ, Link MS, Panchal AR, Pelter MM, Del Rios M, Rodriguez AJ, Perman SM, Sanko S, Kotini-Shah P, Kurz MC. Part 9: Adult Advanced Life Support: 2025 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation. 2025 Oct 21;152(16_suppl_2):S538-S577. doi: 10.1161/CIR.0000000000001376. Epub 2025 Oct 22. PMID: 41122884.

Summarized by Meg Joyce, MS3 | Edited by Meg Joyce & Ahmed Abdel-Hafiz, NREMT-P

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