What is the management of ventricular tachycardia (Vtach)?

Management of Ventricular Tachycardia

Direct current cardioversion is the recommended first-line treatment for patients presenting with ventricular tachycardia and hemodynamic instability. 1

Initial Assessment and Classification

The management of ventricular tachycardia (VT) depends primarily on the patient's hemodynamic stability:

Hemodynamically Unstable VT

• Characterized by:
  • Hypotension
  • Altered mental status
  • Signs of shock
  • Chest pain
  • Heart failure symptoms

Hemodynamically Stable VT

• Patient maintains adequate blood pressure
• No significant symptoms of compromised perfusion

Acute Management Algorithm

For Hemodynamically Unstable VT:

1. Immediate synchronized cardioversion (Class I, Level C recommendation)
   • Begin with maximum output
   • Sedate patient if conscious and time permits 1
   • Place defibrillator patches at least 8 cm from ICD generator if present

For Hemodynamically Stable VT:

1. Electrical cardioversion remains first-line approach even in stable patients 1

2. Pharmacological options if cardioversion is delayed or for refractory cases:

   • Intravenous amiodarone: Recommended for patients with heart failure or suspected ischemia

     • Loading dose: 150 mg over 10 minutes
     • Maintenance: 1 mg/min for 6 hours, then 0.5 mg/min 2

   • Intravenous procainamide: Consider in patients without severe heart failure or acute MI

     • Dosage: 10 mg/kg at 50-100 mg/min IV over 10-20 min 3
     • Monitor blood pressure and ECG during administration

   • Intravenous lidocaine: Less effective but may be considered

Post-Conversion Management

1. Maintenance antiarrhythmic therapy after successful conversion:

   • Continue IV amiodarone infusion at 0.5 mg/min (720 mg/24 hours) 2
   • For breakthrough episodes: 150 mg supplemental infusions of amiodarone over 10 minutes 2

2. Identify and treat underlying causes:

   • Acute myocardial ischemia
   • Electrolyte abnormalities
   • Drug toxicity
   • Structural heart disease

Long-term Management

1. Catheter ablation:

   • Urgent catheter ablation is recommended in patients with scar-related heart disease presenting with incessant VT or electrical storm (Class I, Level B) 1
   • Recommended for patients with ischemic heart disease and recurrent ICD shocks (Class I, Level B) 1
   • Should be considered after first episode of sustained VT in patients with ischemic heart disease and ICD (Class IIa, Level B) 1

2. Implantable Cardioverter Defibrillator (ICD):

   • Indicated for secondary prevention in survivors of VT/VF not due to reversible causes
   • Important to note that even "stable" VT is associated with high mortality and may warrant ICD therapy 4

Special Considerations

• Polymorphic VT: Often associated with acute myocardial ischemia, channelopathies, or ventricular hypertrophy; may require different management approach 1

• Purkinje-fiber triggered polymorphic VT: May be amenable to catheter ablation in drug-refractory cases 1

• Electrical storm: Defined as ≥3 episodes of sustained VT/VF within 24 hours; requires aggressive management including sedation, antiarrhythmic drugs, and consideration of urgent ablation

Pitfalls and Caveats

• Do not delay cardioversion in unstable patients while attempting pharmacological therapy
• Avoid exceeding recommended infusion rates for amiodarone (maximum initial rate 30 mg/min) as this can lead to hepatocellular necrosis and acute renal failure 2
• For amiodarone infusions longer than 1 hour, do not exceed concentrations of 2 mg/mL unless using a central venous catheter 2
• Even "stable" VT should not be considered benign, as it is associated with high mortality and may indicate substrate capable of producing more malignant arrhythmias 4
• High VT burden is associated with increased mortality, though the causal relationship remains unclear 5