01Approach to the Critical Patient/attcp67

Immediate resuscitation

›Pulseless TdP or degeneration to VF

›Unsynchronized defibrillation immediately

›200 J biphasic first shock

›ACLS protocol continuation if no ROSC

›CPR between shocks

›Minimize interruptions

›High-quality compressions at 100-120 per minute

›IV magnesium sulfate 2 g IV push during resuscitation

›Class IIb recommendation for polymorphic VT with long QT

›Hemodynamically unstable TdP with pulse

›Synchronized cardioversion if patient deteriorating rapidly

›Sedation if time allows

›100-200 J biphasic

›IV magnesium sulfate 1-2 g IV over 1-2 minutes

›First-line even with normal serum magnesium level

›AHA 2025 ACLS guideline recommendation

Monitoring targets

›Continuous cardiac monitoring priorities

›Continuous 12-lead telemetry or 5-lead monitoring

›QTc measurement every 4-6 hours

›Alert threshold QTc >500 ms

›Defibrillator at bedside with pads applied

›Immediate defibrillation capability mandatory

›AHA/ACC guideline requirement for all TdP admissions

›Pulse oximetry continuous

›SpO2 target >94%

›Supplemental oxygen if desaturating

›Hemodynamic targets

›Heart rate target 90-110 bpm to shorten QT interval

›Pause-dependent TdP worsens with bradycardia

›Overdrive pacing or isoproterenol to achieve rate

›MAP >65 mmHg during active arrhythmia

›IV fluid resuscitation for hypovolemia

›Vasopressors if refractory hypotension

Immediate stabilization steps

›Airway and breathing

›Airway protection if altered mental status from arrhythmia

›GCS <8 or inability to protect airway

›Rapid sequence intubation avoiding QT-prolonging agents

›Succinylcholine preferred over rocuronium for RSI if needed

›Avoid ketamine; propofol acceptable induction agent

›Medication cessation

›Immediate discontinuation of all QT-prolonging drugs

›Antiarrhythmics: sotalol, dofetilide, quinidine, procainamide, ibutilide

›Antibiotics: erythromycin, clarithromycin, azithromycin, moxifloxacin, fluoroquinolones

›Antipsychotics: haloperidol, thioridazine, chlorpromazine

›Antidepressants: citalopram, escitalopram at high doses

›Others: methadone, ondansetron, droperidol

›Review CredibleMeds database for risk classification

›Known Risk, Conditional Risk, and Possible Risk categories

›Electrolyte correction

›Potassium target 4.5-5.0 mmol/l

›IV potassium chloride 10-20 mmol/hour via central access

›Oral supplementation if able and mild hypokalemia

›Magnesium target >1.0 mmol/l

›IV magnesium sulfate 2-4 g over 20-30 minutes if deficient

›Maintain even in normal serum levels during acute TdP

Consult triggers

›Mandatory electrophysiology consultation

›All confirmed TdP episodes

›Recurrent TdP despite initial therapy

›Suspected congenital long QT syndrome

›Electrical storm (3 or more sustained VT/VF episodes in 24 hours)

›JACC 2023 electrical storm management guideline

›Cardiology consultation

›Structural heart disease evaluation

›Reduced ejection fraction as TdP risk factor

›ICD consideration for congenital LQTS

›Pacemaker or ICD programming if device present

›Optimize rate support to suppress pause-dependent TdP

02History/hx81

Presenting symptoms

›Primary symptom complex

›Palpitations

›Paroxysmal onset

›Racing, fluttering, or irregular sensation

›Presyncope or syncope

›Duration of loss of consciousness

›Preceding lightheadedness or dizziness

›Seizure-like activity

›Convulsive syncope from cerebral hypoperfusion

›Important mimic: true epilepsy vs cardiac syncope

›Cardiac arrest

›Circumstances of arrest

›Witnessed or unwitnessed

Timing and triggers

›Episode characteristics

›Paroxysmal self-terminating pattern typical

›Episodes usually <30 seconds

›May cluster as electrical storm

›Recent medication changes

›New QT-prolonging drug initiation

›Dose increase of existing QT-prolonging drug

›Recent illness with electrolyte losses

›Vomiting or diarrhea

›Fasting or poor oral intake

›Hospitalization context

›Recent inpatient stay with new medications

›Drug-drug interactions during hospitalization

Medication history

›QT-prolonging agent exposure

›All prescription, OTC, and herbal medications

›Specific agents per CredibleMeds known-risk list

›Concomitant use of two or more QT-prolonging drugs

›Antiarrhythmic drug use

›Sotalol, dofetilide, quinidine, procainamide, ibutilide

›Class IA and Class III agents carry highest TdP risk

›Antibiotic use

›Macrolides: erythromycin, clarithromycin, azithromycin

›Fluoroquinolones: moxifloxacin, levofloxacin

›Psychiatric medication use

›Antipsychotics: haloperidol, thioridazine, pimozide

›Antidepressants: high-dose citalopram or escitalopram

›Methadone or opioid maintenance therapy

›High-dose methadone strongly associated with QT prolongation

›Cocaine use also implicated

Risk factors

›Patient-specific risk factors per AHA Scientific Statement

›Female sex

›Longer baseline QTc than males

›Two-fold higher risk of drug-induced TdP

›Age >65 years

›Impaired drug clearance

›Polypharmacy burden

›QTc >500 ms or increase >=60 ms from baseline

›High-risk threshold per AHA/ACC guidelines

›Immediate drug discontinuation indicated

›Bradycardia

›Heart rate <50 bpm prolongs QT interval

›Pause-dependent TdP mechanism

›Electrolyte abnormalities

›Hypokalemia most common precipitant

›Hypomagnesemia and hypocalcemia also contributory

›Heart failure with reduced ejection fraction

›Reduced repolarization reserve

›Increased sensitivity to QT-prolonging drugs

›Renal or hepatic impairment

›Impaired drug clearance

›Elevated drug levels at standard doses

›Acute myocardial infarction

›Ischemia-related repolarization abnormalities

›Electrolyte shifts during acute MI

Family and prior history

›Family history red flags for congenital LQTS

›Sudden cardiac death in family members <40 years

›Unexplained drowning in young relatives

›Seizures in young family members may be cardiac syncope

›Family history of syncope or known LQTS diagnosis

›Approximately 30% of drug-induced TdP patients carry LQTS gene mutations

›Genetic testing consideration if family history positive

›Personal history

›Prior drug-induced TdP or QT prolongation episodes

›Highest risk factor for recurrence

›Document as formal drug allergy/adverse reaction

›Congenital LQTS personal diagnosis

›Known subtype if genotyped

›Current ICD status

03Physical Exam/exam57

Vital signs

›Hemodynamic assessment

›Heart rate

›Bradycardia as precipitant recognition

›Tachycardia during active TdP episode

›Blood pressure

›Hypotension during VT episodes

›SBP <90 mmHg as hemodynamic instability threshold

›Oxygen saturation

›Desaturation during sustained arrhythmia

›Post-arrest hypoxemia

›Temperature

›Fever elevating medication levels

›Hypothyroidism association

Cardiovascular exam

›Rhythm assessment

›Irregular rhythm during TdP or ectopy

›Pause followed by PVC triggering TdP

›Short-long-short initiating sequence

›Heart sounds

›S3 or S4 suggesting structural disease or heart failure

›Murmur suggesting valvular disease

›Signs of heart failure

›Jugular venous distension

›Elevated JVP >4 cm above sternal angle

›Kussmaul sign if right heart compromise

›Peripheral edema

›Bilateral pitting edema

04Differential Diagnosis/ddx40

Life-threatening polymorphic VT diagnoses

›Torsades de Pointes

›ICD-10 I49.2 (ventricular fibrillation and flutter)

›Polymorphic VT with prolonged QTc on baseline ECG

›Twisting QRS amplitude around isoelectric line

›Ischemic polymorphic VT

›ICD-10 I21.9 (acute MI associated)

›Normal or borderline QTc without drug exposure

›Acute MI or ischemia on ECG or troponin elevation

›Ventricular fibrillation

›ICD-10 I49.01

›Pulseless; chaotic baseline without organized QRS

›May be difficult to distinguish from sustained TdP

›Catecholaminergic polymorphic VT

›ICD-10 I47.2

›Exercise or emotional stress triggered

›Normal resting QT interval

›Bidirectional or polymorphic VT on exercise testing

Rare polymorphic VT subtypes

›Short QT syndrome

›QTc <330-370 ms on ECG

›Polymorphic VT and sudden cardiac death risk

›Opposite of LQTS; treatment differs

›Short-coupled polymorphic VT

›Initiating PVC coupling interval <300-360 ms

›Normal QT interval

›Behaves like ischemic polymorphic VT, not TdP

›Bidirectional VT

05Laboratory Tests/lt49

Electrolytes

›Potassium

›Stat serum potassium in all TdP

›Target 4.5-5.0 mmol/l during acute TdP management

›Hypokalemia most common reversible precipitant

›Potassium replacement strategy

›IV replacement preferred in acute setting

›Central access for rates >10 mmol/hour

›Magnesium

›Stat serum magnesium

›Target serum magnesium >1.0 mmol/l

›IV magnesium therapeutic even with normal serum level

›Magnesium replacement

›IV magnesium sulfate 2-4 g over 20-30 minutes

›Repeat dosing if refractory TdP

›Calcium

›Ionized calcium or total calcium

›Hypocalcemia prolongs QT interval

›IV calcium gluconate 1-2 g if hypocalcemic

Cardiac biomarkers

›Troponin

›High-sensitivity troponin I or T

›Rule out acute MI as cause of ischemic polymorphic VT

›Serial measurement if initial elevated

›Creatine kinase

›Elevated after prolonged resuscitation or cardioversion

›Baseline useful in electrical storm management

06Diagnostic Tests/dt83

Scoring Systems

›Tisdale Risk Score for QT prolongation

›Risk stratification for drug-induced QT prolongation

›Age >=68 years: 1 point

›Female sex: 1 point

›Loop diuretic use: 1 point

›Serum potassium <=3.5 mmol/l: 2 points

›Admission QTc >=450 ms: 2 points

›Acute MI: 2 points

›Sepsis: 3 points

›Heart failure: 3 points

›One QT-prolonging drug: 3 points

›Two or more QT-prolonging drugs: 6 points

›Score interpretation

›Low risk: <7 points

›Moderate risk: 7-10 points

›High risk: >10 points

›LQTS Schwartz Score (congenital LQTS diagnosis)

›ECG findings component

›QTc >=480 ms: 3 points

›QTc 460-479 ms: 2 points

›QTc 450-459 ms (males): 1 point

›T-wave alternans: 1 point

›Notched T wave in 3 leads: 1 point

›Low heart rate for age: 0.5 points

›Clinical history component

›Syncope with stress: 2 points

›Syncope without stress: 1 point

›Congenital deafness: 0.5 points

›Family history component

›Family member with LQTS: 1 point

›Unexplained sudden cardiac death <30 years: 0.5 points

›Score interpretation

›<=1 point: Low probability LQTS

›1.5-3 points: Intermediate probability

›>3.5 points: High probability LQTS

MRI

›Cardiac MRI indications in TdP evaluation

›Suspected structural heart disease not fully characterized by echo

›Arrhythmogenic cardiomyopathy evaluation

›Late gadolinium enhancement for fibrosis/scar

›Myocarditis evaluation

›T2 signal for myocardial edema

›Lake Louise criteria for myocarditis diagnosis

›Hypertrophic cardiomyopathy with coexisting LQTS

›Wall thickness quantification

›Outflow tract obstruction assessment

›Limitations in acute TdP

›Not a first-line or emergent test for TdP

›Echocardiography preferred in acute setting

›MRI considered after stabilization

CT

›CT angiography indications in TdP context

›Coronary CTA if ischemic polymorphic VT in differential

›Exclude significant coronary artery disease

›Not routinely needed if acute MI clearly excluded by ECG and troponin

›CT chest for pulmonary pathology

›Pulmonary embolism if QT prolongation with tachycardia

›Pulmonary edema quantification

›Brain CT if post-arrest or neurological symptoms

›Anoxic brain injury assessment

›Post-resuscitation care planning

›Exclude intracranial pathology as TdP trigger

›Limitations

›No direct role in diagnosing TdP

›ECG is the definitive diagnostic modality

›CT selected based on specific differential and presentation

Ultrasound

›Point-of-care echocardiography

›Indications in TdP

›Structural heart disease assessment

›Left ventricular ejection fraction measurement

›LVEF <35-40% as ICD consideration trigger

›Pericardial effusion exclusion

›Tamponade physiology as cause of shock

›Right ventricular collapse in diastole as tamponade sign

›Valvular assessment

›Significant valvular disease as structural risk factor

›Mitral valve prolapse association with LQTS

›IVC assessment

›Volume status estimation

›IVC <2.1 cm with >50% collapse suggests low CVP

›Guides fluid resuscitation in hypotensive TdP patient

›Lung ultrasound

›Pulmonary edema assessment

›B-lines indicating interstitial fluid

›Guides diuresis vs fluid administration decision

07Disposition/dispo48

ICU admission

›Indications for cardiac ICU or monitored ICU

›Sustained TdP requiring cardioversion or defibrillation

›Continuous monitoring with defibrillator at bedside

›Immediate defibrillation capability required per AHA/ACC

›Recurrent TdP episodes

›Electrical storm: three or more sustained VT/VF in 24 hours

›JACC 2023 multidisciplinary management recommendation

›Hemodynamic instability

›Hypotension requiring vasopressors

›Signs of cardiogenic shock

›Need for overdrive pacing

›Transvenous pacemaker placement

›ICU-level nursing for pacemaker management

›Isoproterenol infusion requirement

›Continuous infusion titration requires ICU setting

›Hemodynamic monitoring during isoproterenol

Telemetry admission

›Indications for step-down or telemetry

›Single self-terminating episode with identified correctable precipitant

›Electrolyte abnormalities being corrected

›Offending drug discontinued

›Stable hemodynamics throughout

›No hypotension or syncope since presentation

›QTc improving with intervention

›Requires continuous QTc monitoring until trending to normal

›Electrophysiology consultation before downgrading monitoring

08Treatment/t92

Immediate pharmacotherapy

›Magnesium sulfate IV

›First-line treatment for TdP regardless of serum level

›1-2 g IV over 1-2 minutes for active TdP

›May repeat 1-2 g IV 5-15 minutes later if arrhythmia continues

›AHA 2025 ACLS guideline recommendation

›Maintenance infusion if recurrent TdP

›0.5-1 g/hour continuous IV infusion

›Titrate to serum magnesium >1.0 mmol/l

›Mechanism

›Blocks calcium channels reducing early afterdepolarizations

›Stabilizes myocardial membrane without QT prolongation

Heart rate augmentation

›Isoproterenol infusion

›Indication: acquired LQTS with bradycardia-dependent TdP

›Temporizing measure while awaiting transvenous pacing

›Avoid in congenital LQTS (catecholamine-sensitive subtypes)

›Dosing

›Start at 2 mcg/min IV infusion

›Titrate to heart rate 90-110 bpm

›Maximum 10 mcg/min

›Target

›Increased heart rate shortens QT interval

›Eliminates pause-dependent TdP mechanism

›Contraindications

›Congenital LQT1 and LQT2: catecholamines may trigger TdP

›Hypertension or ischemic heart disease: use with caution

›Temporary cardiac pacing

›Overdrive pacing: most effective for refractory pause-dependent TdP

›Transvenous atrial or ventricular pacing preferred

›Rate 90-110 bpm to suppress TdP

›Class I recommendation per AHA/ACC/HRS 2017 guideline

›External transcutaneous pacing as bridge

›Use if transvenous pacing delayed

›Sedation required for external pacing tolerance

Electrolyte replacement protocols

›Potassium repletion

›IV potassium chloride for moderate to severe hypokalemia

›Rate 10-20 mmol/hour via peripheral IV

›Rate up to 40 mmol/hour via central access for severe depletion

›Cardiac monitoring mandatory during IV replacement

›Target serum potassium 4.5-5.0 mmol/l during active TdP

›Oral supplementation 40-80 mmol/day for maintenance

›Recheck electrolytes 2-4 hours after IV replacement

›Magnesium repletion

›IV magnesium sulfate 2-4 g over 20-30 minutes for deficiency

›Repeat 2 g every 4-6 hours if hypomagnesemia persists

›Monitor deep tendon reflexes if very high doses given

›Oral magnesium oxide 400-800 mg daily for maintenance

›Poor GI absorption limits oral replacement in acute setting

Refractory TdP management

›Mexiletine

›Indication: refractory TdP, particularly LQT2 and LQT3 subtypes

›Oral mexiletine 200-300 mg three times daily

›IV formulation available in some jurisdictions

›Shortens QT interval by blocking sodium channels

›Monitoring during mexiletine initiation

›Serial ECG for QTc and QRS changes

›LFTs as hepatotoxicity risk

›Lidocaine IV

›Adjunct for refractory TdP in acquired LQTS

›1-1.5 mg/kg IV bolus

›Maintenance infusion 1-4 mg/min

›Class IIb evidence base

›Mechanism

›Sodium channel blockade shortens QT

›Less effective than mexiletine for congenital LQT3

Congenital LQTS subtype-specific treatment

›LQT1 management

›Beta-blockers are first-line therapy

›Nadolol 0.5-1.0 mg/kg/day in adults

›Propranolol 2-3 mg/kg/day as alternative

›Class I recommendation for LQT1 and LQT2

›Avoid sympathetic triggers

›Swimming and exercise restriction in high-risk patients

›Epinephrine avoidance in local anesthetics

›LQT2 management

›Beta-blockers plus potassium supplementation

›Maintain potassium >4.0 mmol/l

›Acoustic triggers avoidance (alarm clocks, sudden noises)

›Left cardiac sympathetic denervation

›Reserved for refractory cases or ICD candidates

›LQT3 management

›Sodium channel blockers preferred over beta-blockers

›Mexiletine 200-300 mg three times daily

›Flecainide 100-200 mg twice daily as alternative

›Beta-blockers less effective for LQT3

›Arrhythmia occurs at rest/sleep, not exercise

Treatments to avoid

›Contraindicated interventions

›Standard antiarrhythmics (amiodarone, procainamide, sotalol)

›These prolong QT interval and worsen TdP

›Critical pitfall: amiodarone is first-line for most VT but contraindicated in TdP

›Acute beta-blockers in acquired TdP

›May precipitate bradycardia and worsen pause-dependent TdP

›Exception: beta-blockers ARE first-line for congenital LQTS

›Concomitant QT-prolonging drug combinations

›Pharmacodynamic interaction multiplies TdP risk

09Special Populations/sp67

Pregnancy

›Physiologic considerations

›QT interval lengthens during pregnancy

›Increased estrogen prolongs QTc

›Higher baseline risk for drug-induced TdP

›Hemodynamic changes

›Increased cardiac output and plasma volume

›Altered drug pharmacokinetics

›Congenital LQTS management in pregnancy

›Beta-blockers continued throughout pregnancy

›Nadolol: limited placental transfer, preferred

›Propranolol: increased risk of intrauterine growth restriction

›Do NOT discontinue beta-blockers in pregnancy

›Risk of postpartum TdP highest in LQT2

›QTc lengthens further after delivery

›Intensive monitoring postpartum for LQTS patients

›Drug-induced TdP in pregnancy

›Immediate magnesium sulfate use is safe

›Already used routinely in obstetrics for preeclampsia

›Monitor for hypermagnesemia in mother and neonate

›Isoproterenol category considerations

›Limited fetal data; use if maternal benefit outweighs risk

›Defibrillation and cardioversion safe in pregnancy

›Fetal monitoring during and after cardioversion

›Maternal resuscitation takes priority

Geriatric

›Increased TdP risk in elderly

›Age >65 years is independent risk factor per AHA statement

10Background/b86

Epidemiology

›Incidence and prevalence

›Drug-induced TdP incidence

›Rare in general population without risk factors per AHA statement

›Estimated 1-8% incidence with Class IA antiarrhythmics

›Sotalol TdP incidence 1.8-4.7% in clinical trials

›Congenital LQTS prevalence

›Approximately 1 in 2,000 in general population

›Estimated 3,000-4,000 sudden deaths per year in US attributed to LQTS

›Sex distribution

›Female predominance in drug-induced TdP (2:1 female:male ratio)

›Females have longer baseline QTc due to hormonal differences

›Mortality and morbidity

›Untreated TdP mortality

›Risk of degeneration to VF approximately 10-20%

›Sudden cardiac death if VF not immediately treated

›Treated TdP prognosis

›Excellent if precipitant identified and removed

›QTc normalizes within days after drug discontinuation

Pathophysiology

›QT interval physiology

›QTc represents total ventricular repolarization time

›Normal QTc: <440 ms males, <460 ms females

›QTc calculated by Bazett formula: QT/sqrt(RR interval)

›Fridericia formula preferred at extreme heart rates

›Repolarization reserve

›Multiple redundant repolarization channels provide safety margin

›Reduced reserve: female sex, heart failure, genetic variants

›Cellular mechanism

›Early afterdepolarizations (EADs) as trigger

›EADs arise during phase 2 or 3 of cardiac action potential

›JACC Clinical Electrophysiology 2024 review

›Triggered activity from EADs initiates TdP

›Transmural dispersion of repolarization as substrate

›Heterogeneous repolarization across myocardial wall

›M cells (mid-myocardial) have longest action potential duration

›Creates functional re-entry substrate for sustained TdP

›Pause-dependent (bradycardia-dependent) mechanism

›Long RR interval prolongs subsequent action potential duration

›Short-long-short sequence initiates EAD and TdP

›Explains why bradycardia is a major precipitant

›Congenital LQTS genetics

›Major subtypes

›LQT1: KCNQ1 gene mutation (slow IKs potassium channel)

›LQT2: KCNH2 gene mutation (rapid IKr potassium channel)

›LQT3: SCN5A gene mutation (sodium channel, late inward current)

›Nearly 30% of drug-induced TdP patients carry subclinical LQTS mutations

›Explains individual susceptibility at therapeutic drug doses

›Supports genetic testing in all recurrent TdP cases

›Drug-induced mechanisms

›IKr potassium channel blockade

›Most QT-prolonging drugs block IKr (hERG channel)

›IKr block reduces repolarizing current, prolonging QT

›Class IA and III antiarrhythmics, many non-cardiac drugs

›CYP3A4 drug interactions

›Grapefruit juice inhibits CYP3A4

›Elevated drug levels at standard doses

›Common mechanism for drug-drug interaction-induced TdP

Therapeutic Considerations

›Acquired vs congenital LQTS treatment differences

›Acquired LQTS (drug-induced)

›Remove precipitant as primary treatment

›Magnesium, rate acceleration, electrolyte correction

›Beta-blockers may worsen bradycardia-dependent TdP acutely

›Congenital LQTS

›Beta-blockers first-line for LQT1 and LQT2

›Sodium channel blockers for LQT3

›ICD for secondary prevention after cardiac arrest

›Magnesium mechanism of action

›Suppresses early afterdepolarizations

›Blocks L-type calcium channels

›Reduces triggered activity without prolonging QT

›Effective even with normal serum magnesium

›Therapeutic effect independent of serum level

›Supports empiric use in all TdP

›Overdrive pacing rationale

›Rate acceleration shortens QT interval

›QT-heart rate relationship: faster rates shorten QT

›Eliminates long pauses that trigger EADs

›Permanent pacing for chronic bradycardia-dependent TdP

›Prevents pause-dependent triggering

›Rate 90-100 bpm programmed minimum

›CredibleMeds risk classification system

›Known Risk: drugs with substantial evidence for TdP

›Sotalol, dofetilide, quinidine, erythromycin, methadone

›Conditional Risk: drugs with TdP risk under specific conditions

›Azithromycin, ondansetron, fluconazole

›Possible Risk: limited evidence or plausible mechanism

›www.crediblemeds.org for complete current list

11Patient Discharge Instructions/pdi41

copy discharge instructions

›About your diagnosis

›You were diagnosed with Torsades de Pointes, a serious heart rhythm abnormality caused by prolonged electrical recovery time in your heart

›This abnormal rhythm can cause dizziness, fainting, or cardiac arrest

›The cause was identified and has been corrected or is being managed

›Medications to avoid permanently

›You must never take the following medication that caused your heart rhythm problem

›This drug has been added to your medical record as a formal allergy or adverse drug reaction

›Tell every doctor, dentist, and pharmacist about this drug allergy

›Carry a list of all QT-prolonging drugs to avoid

›A complete up-to-date list is available at www.crediblemeds.org

›Check any new medication against this list before taking it

›Electrolyte and diet precautions

›Maintain adequate potassium and magnesium in your diet

›High-potassium foods: bananas, oranges, potatoes, spinach

›Magnesium-rich foods: nuts, seeds, leafy greens, whole grains

›Stay well hydrated especially during illness

›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

12References/r27

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

Evidence & Review