What is the treatment for Ventricular Tachycardia (VT)?

Treatment of Ventricular Tachycardia (VT)

For hemodynamically unstable VT, immediate direct current cardioversion is the definitive treatment; for stable monomorphic VT, intravenous procainamide is the most effective pharmacological option, though electrical cardioversion remains superior. 1, 2

Initial Assessment: Hemodynamic Stability

The critical first step is determining whether the patient has a pulse and assessing hemodynamic stability 3:

• Unstable VT is defined by hypotension (systolic BP ≤90 mmHg), altered mental status/syncope, chest pain, heart failure, or severe symptoms 1, 3
• Stable VT means the patient maintains adequate perfusion despite the arrhythmia 1
• Pulseless VT should be treated identically to ventricular fibrillation with immediate unsynchronized defibrillation 1

Treatment Algorithm for Unstable VT (with pulse)

Immediate synchronized cardioversion is mandatory 1:

• Provide sedation immediately if the patient is conscious 1, 3
• Start with 100 J, then escalate to 200 J, then 360 J if needed 1, 3
• Do NOT delay cardioversion for medication administration 1

After successful cardioversion, consider antiarrhythmic infusion to prevent recurrence 3:

• Amiodarone: 150 mg IV over 10 minutes, then 1 mg/min for 6 hours, then 0.5 mg/min maintenance 4
• Lidocaine: 1-1.5 mg/kg IV bolus (max 100 mg), then 2-4 mg/min infusion 3, 5

Treatment Algorithm for Stable Monomorphic VT

First-line approach remains electrical cardioversion even in stable patients, as it is most efficacious 1, 2. However, if pharmacological management is chosen:

Preferred Medication: Procainamide

Procainamide demonstrates the greatest efficacy for stable monomorphic VT 1, 2:

• Dose: 10 mg/kg IV at 50-100 mg/min over 10-20 minutes 1, 2
• Monitor blood pressure and QRS width continuously 1, 2
• Stop infusion if hypotension develops, QRS widens >50%, or arrhythmia terminates 1
• Contraindications: severe heart failure or acute myocardial infarction 1

Alternative Medications

Amiodarone (Class IIa recommendation) 1:

• Loading: 150 mg IV over 10 minutes (may repeat once) 1, 4
• Maintenance: 1 mg/min for 6 hours, then 0.5 mg/min 4
• Preferred when heart failure or ischemia is present 1
• Less effective for immediate termination but useful for preventing recurrence 1, 4

Lidocaine (Class IIb recommendation) 1, 3:

• Initial: 50 mg IV over 2 minutes, repeat every 5 minutes to total 200 mg 3
• Maintenance: 2 mg/min infusion 3
• Specifically indicated when VT is associated with acute myocardial ischemia 1, 3
• Only moderately effective compared to other agents 1

Sotalol (Class IIb recommendation) 1:

• May be considered for stable monomorphic VT including in acute MI 1
• Limited evidence compared to other agents 1

Treatment of Polymorphic VT (with pulse)

Polymorphic VT requires different management based on QT interval 1:

Normal QT (Ischemic Polymorphic VT)

• Immediate cardioversion if hemodynamically unstable 1
• Beta-blockers IV are first-line pharmacological therapy 1
• Urgent angiography with revascularization should be considered 1
• Amiodarone loading is useful for recurrent episodes 1
• Lidocaine may be reasonable if associated with acute MI 1

Prolonged QT (Torsades de Pointes)

• Magnesium sulfate: 2 g IV bolus over 1-2 minutes 1, 3
• Correct electrolyte abnormalities (potassium, magnesium) 1
• Discontinue all QT-prolonging drugs immediately 1
• Consider overdrive pacing or isoproterenol to increase heart rate 1

Critical Contraindications and Pitfalls

Never use calcium channel blockers (verapamil, diltiazem) for wide-complex tachycardia of unknown origin or VT, especially with myocardial dysfunction—this can precipitate cardiovascular collapse 1, 3

Do not use synchronized cardioversion for polymorphic VT or pulseless VT—these require unsynchronized high-energy defibrillation 1

Avoid procainamide in patients with severe heart failure or acute MI—use amiodarone instead 1

Monitor for procainamide toxicity: hypotension and QRS widening >50% require immediate discontinuation 1, 2

Reduce lidocaine dosing in patients with heart failure, cardiogenic shock, or after 24-48 hours of infusion 3

Special Considerations

Correct reversible causes immediately 1:

• Hypokalemia and hypomagnesemia 1
• Acute ischemia 1
• Drug toxicity 1

For recurrent/refractory VT 1:

• Consider transvenous catheter pace termination 1
• Beta-blockers may reduce recurrence during electrical storm 1
• Bretylium (5-10 mg/kg IV) may be used when other agents fail 3, 6

ICD therapy should be considered for secondary prevention in patients with recurrent VT and structural heart disease or reduced left ventricular function 1