Contributor: Aaron Lessen, MD
Educational Pearls:
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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
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Torsades de pointes is polymorphic ventricular tachycardia occurring in the setting of a prolonged QT/QTc
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Risk of torsades increases substantially when QTc exceeds 500ms
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Causes:
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Common reversible causes include QT-prolonging medications, hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, and structural heart disease
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Congenital causes of a prolonged QT interval are primarily inherited genetic mutations affecting cardiac myocyte ion channels leading to delayed ventricular repolarization
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Treatment:
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Stop any QT-prolonging medications and correct electrolytes
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IV magnesium to suppress recurrent torsades
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Increasing the heart rate with isoproterenol or temporary pacing can prevent the pauses that trigger recurrent episodes
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If the rhythm degenerates into ventricular fibrillation → defibrillate
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References
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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.
