Vomiting and diarrhea deplete potassium and magnesium
Seek medical care promptly if unable to keep fluids down
Avoid grapefruit juice
Increases blood levels of many heart medications
Limit alcohol consumption
Can cause electrolyte depletion and worsen QT prolongation
Activity and lifestyle
Follow up with your heart specialist before returning to strenuous exercise
If congenital long QT syndrome diagnosed, specific activity restrictions apply
Swimming precautions: do not swim alone if you have congenital long QT syndrome
Outpatient follow-up
Cardiology or electrophysiology follow-up within 1-2 weeks
ECG to confirm QTc normalization
If congenital long QT syndrome suspected, genetic testing may be arranged
ECG monitoring every 3-6 months if on chronic QT-prolonging medications
Return to emergency department immediately if
Palpitations, fluttering, or rapid irregular heartbeat
Do not wait to see if it resolves
Call 911 or have someone drive you
Dizziness, lightheadedness, or near-fainting
Sit or lie down immediately and call for help
Loss of consciousness or fainting
Emergency services required immediately
Seizure-like activity in yourself or a family member
May represent cardiac arrhythmia, not epilepsy
References
Guidelines and key sources
AHA 2025 ACLS Guidelines
Wigginton JG, Agarwal S, Bartos JA, et al. Part 9: Adult Advanced Life Support: 2025 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation. 2025
Defibrillation and magnesium recommendations for TdP
AHA 2017 Ventricular Arrhythmia Guideline
Al-Khatib SM, Stevenson WG, Ackerman MJ, et al. 2017 AHA/ACC/HRS Guideline for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death. Journal of the American College of Cardiology. 2018
Overdrive pacing, ICD, and beta-blocker recommendations for LQTS
AHA Drug-Induced Arrhythmias Scientific Statement
Tisdale JE, Chung MK, Campbell KB, et al. Drug-Induced Arrhythmias: A Scientific Statement From the American Heart Association. Circulation. 2020
Risk factors, drug lists, and electrolyte targets for drug-induced TdP
AHA/ACCF TdP Prevention Scientific Statement
Drew BJ, Ackerman MJ, Funk M, et al. Prevention of Torsade De Pointes in Hospital Settings: A Scientific Statement From the American Heart Association and the American College of Cardiology Foundation. Circulation. 2010
Hospital QTc monitoring protocols and risk stratification
JACC Electrical Storm Review
Jentzer JC, Noseworthy PA, Kashou AH, et al. Multidisciplinary Critical Care Management of Electrical Storm: JACC State-of-the-Art Review. Journal of the American College of Cardiology. 2023
Recurrent TdP and electrical storm management
Pharmacological Treatment Review
Thomas SH, Behr ER. Pharmacological Treatment of Acquired QT Prolongation and Torsades De Pointes. British Journal of Clinical Pharmacology. 2016
Magnesium, isoproterenol, and mexiletine evidence
Differential Diagnosis Reference
Rosso R, Hochstadt A, Viskin D, et al. Polymorphic Ventricular Tachycardia, Ischaemic Ventricular Fibrillation, and Torsade De Pointes: Importance of the QT and the Coupling Interval in the Differential Diagnosis. European Heart Journal. 2021
Coupling interval criteria distinguishing TdP from ischemic polymorphic VT
Inherited Arrhythmia Acute Management
Laksman Z, Barichello S, Roston TM, Deyell MW, Krahn AD. Acute Management of Ventricular Arrhythmia In Patients With Suspected Inherited Heart Rhythm Disorders. JACC Clinical Electrophysiology. 2019
Subtype-specific management of congenital LQTS
EAD Mechanism Review
Lerman BB, Markowitz SM, Cheung JW, Thomas G, Ip JE. Ventricular Tachycardia Due to Triggered Activity: Role of Early and Delayed Afterdepolarizations. JACC Clinical Electrophysiology. 2024
Cellular mechanism of TdP via early afterdepolarizations
SymptomDx is an educational tool for medical professionals. It does not replace clinical judgment. Verify all clinical data and drug dosages with authoritative sources.