What is the treatment for a patient presenting with ventricular tachycardia (VTACH)?

Treatment of Ventricular Tachycardia

For hemodynamically unstable VT (hypotension with systolic BP ≤90 mmHg, altered mental status, chest pain, acute heart failure, or shock), perform immediate synchronized DC cardioversion starting at 100J without delay. 1, 2, 3

Initial Assessment: Determine Hemodynamic Stability

The critical first step is rapid assessment of hemodynamic status, which dictates your entire treatment pathway 1, 2:

Unstable VT is defined by:

• Systolic blood pressure ≤90 mmHg 2
• Altered mental status or signs of shock 1, 3
• Chest pain or acute heart failure 2
• Heart rate ≥150 beats/min 2

Key pitfall: Always presume wide-QRS tachycardia is VT if the diagnosis is unclear—when in doubt, treat as VT 4, 2, 3

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Hemodynamically Unstable VT: Immediate Cardioversion

Synchronized DC cardioversion is the definitive treatment for unstable monomorphic VT 4, 1, 2, 3:

Cardioversion Protocol:

• Start with 100J synchronized shock 2, 3
• If unsuccessful, escalate to 200J 2
• If still unsuccessful, escalate to 360J 2
• For conscious but unstable patients, provide immediate sedation before cardioversion 1, 3

Special Consideration for Polymorphic VT:

• Use unsynchronized high-energy shocks (defibrillation doses of 200J) for polymorphic VT that appears similar to VF 3
• Polymorphic VT cannot be reliably synchronized, so treat as VF 4

Post-Cardioversion Management:

• If VT recurs after successful cardioversion, administer antiarrhythmic drugs to prevent reinitiation 1, 3

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Hemodynamically Stable Monomorphic VT: Pharmacologic Approach

For stable monomorphic VT, procainamide is the preferred first-line agent, demonstrating the greatest efficacy for rhythm conversion 1, 2, 3:

First-Line: Procainamide

• Dosing: 10 mg/kg IV at 50-100 mg/min over 10-20 minutes (maximum dose 10-20 mg/kg) 1, 2, 3
• Monitor continuously for hypotension and QRS widening during administration 2
• Contraindications: Avoid in severe heart failure or acute myocardial infarction 4, 1, 2

Second-Line: Amiodarone (When Procainamide Contraindicated)

Amiodarone is preferred in patients with heart failure, suspected ischemia, or impaired left ventricular function 1, 2, 3, 5:

• Loading dose: 150 mg (5 mg/kg) IV over 10 minutes 1, 2
• Maintenance: 1 mg/min infusion for 6 hours, then 0.5 mg/min 1
• Amiodarone reduces life-threatening arrhythmias, required shocks, and symptomatic VT episodes 1, 2
• FDA indication: Initiation of treatment for frequently recurring VF and hemodynamically unstable VT refractory to other therapy 5

Third-Line: Sotalol

• May be considered for hemodynamically stable sustained monomorphic VT, including post-MI patients 4, 1
• Exercise caution due to significant beta-sympatholytic properties 2

Fourth-Line: Lidocaine (Limited Role)

• Only moderately effective and less effective than procainamide, sotalol, or amiodarone 1, 2
• Consider only for VT specifically associated with acute myocardial ischemia or infarction 4

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Polymorphic VT: Distinguish QT Interval

Polymorphic VT with Normal QT (Likely Ischemia-Related):

• IV beta-blockers are first-line 2, 3
• Treat underlying ischemia aggressively with urgent revascularization 2, 3
• IV amiodarone loading is useful for recurrent polymorphic VT in the absence of QT prolongation 3

Polymorphic VT with Prolonged QT (Torsades de Pointes):

• IV magnesium sulfate: 8 mmol bolus followed by 2.5 mmol/h infusion 2, 3
• Overdrive pacing (atrial or ventricular) 3
• Beta-blockers for congenital long QT syndrome 3
• Correct electrolyte abnormalities (potassium, magnesium) 2, 3

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Pulseless VT: Treat as Ventricular Fibrillation

Pulseless VT requires immediate unsynchronized defibrillation using the VF protocol 4, 2:

• Do not attempt synchronization—this may delay or prevent shock delivery 4
• Use high-energy unsynchronized shocks (defibrillation doses) 4

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Critical Pitfalls to Avoid

Never use calcium channel blockers (verapamil, diltiazem) for wide-complex tachycardia of unknown origin or VT with structural heart disease 4, 2, 3:

• These agents may precipitate hemodynamic collapse and worsen outcomes 4, 2, 3
• Only use if absolutely certain of fascicular VT diagnosis 3

Never assume wide-complex tachycardia is supraventricular—always treat as VT when uncertain 4, 2, 3

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Monitoring Requirements During Treatment

• Continuous ECG monitoring is mandatory for all VT treatment 2
• Measure and normalize serum potassium and magnesium before initiating antiarrhythmics 2
• Monitor QTc interval—discontinue drug if QTc prolongs to ≥500 ms 2
• Facility must have cardiac resuscitation capabilities immediately available 2

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Long-Term Management Considerations

Catheter Ablation:

• Urgent catheter ablation is recommended for incessant VT or electrical storm in scar-related heart disease 1, 2, 3
• Consider ablation in patients with ischemic heart disease and recurrent ICD shocks due to sustained VT 1, 3

Beta-Blockers:

• Beta-blockers are the cornerstone for catecholaminergic polymorphic VT 1, 2
• Beta-blockers with or without amiodarone are recommended for VT storm 3

ICD Implantation:

• Consider ICD implantation for secondary prevention in structural heart disease 2