What is the treatment for ventricular tachycardia?

Treatment of Ventricular Tachycardia

The treatment of ventricular tachycardia (VT) requires immediate assessment of pulse and hemodynamic stability, with lidocaine (lignocaine) as first-line pharmacological therapy for sustained VT and synchronized cardioversion for hemodynamically unstable patients. 1

Initial Assessment and Classification

• First determine if the patient has a pulse - pulseless VT is treated using the VF protocol with immediate defibrillation 1
• For VT with pulse, assess for adverse signs: systolic BP ≤ 90 mmHg, chest pain, heart failure, or heart rate ≥ 150 beats/min 1

Treatment Algorithm for VT with Pulse

Hemodynamically Unstable VT (with adverse signs)

• Provide sedation followed by synchronized DC shock (100J, 200J, 360J) 1
• Establish IV access and administer oxygen 1
• If cardioversion fails, administer antiarrhythmic drugs followed by repeated cardioversion attempts 1

Hemodynamically Stable VT

• Lidocaine (Lignocaine): First-line pharmacological treatment 1

  • Initial dose: 50 mg IV over 2 minutes, repeated every 5 minutes to total dose of 200 mg 1
  • If successful, maintain with infusion at 2-4 mg/min 1
  • For cardiac arrest situations, give 100 mg bolus, may repeat after 5-10 minutes 1

• Amiodarone: For VT refractory to lidocaine 1, 2

  • FDA-approved for initiation of treatment and prophylaxis of frequently recurring VF and hemodynamically unstable VT in patients refractory to other therapy 2
  • Dosing: 5 mg/kg (300 mg) over one hour for stable patients 1
  • In life-threatening situations: 300 mg over 15 minutes, repeated after one hour, followed by 15 mg/kg (up to 900 mg) over the next 24 hours 1
  • Higher loading doses (approximately 1000 mg over 24 hours) show better efficacy than lower doses in suppressing recurrent VT 2

• Bretylium: For VT refractory to other agents 1

  • Initial dose: 5 mg/kg diluted with 100 ml dextrose 1
  • If unsuccessful, may administer further dose of 10 mg/kg 1
  • Note: Antiarrhythmic effect may take up to 20 minutes to appear 1

• Magnesium: Particularly effective for VT associated with acute myocardial infarction 1

  • Dose: 8 mmol bolus injection followed by 2.5 mmol/h infusion 1

Comparative Efficacy

• Amiodarone has been shown to be more effective than lidocaine for shock-resistant VT, with 78% immediate termination rate versus 27% for lidocaine 3
• One-hour VT-free survival is significantly better with amiodarone (67%) compared to lidocaine (9%) 3
• 24-hour survival rates: 39% with amiodarone versus 9% with lidocaine 3

Long-term Management

• For patients with recurrent VT, oral amiodarone has shown 69% success rate in preventing recurrence over follow-up periods of 6-52 months 4
• Maintenance dose typically ranges from 200-600 mg daily after appropriate loading 5

Important Considerations and Pitfalls

• Drug Administration: Always follow IV antiarrhythmic drugs with 20 ml bolus of saline to aid delivery to central circulation 1
• Hemodynamic Effects: Amiodarone can cause significant hemodynamic deterioration; monitor closely 6
• Amiodarone Side Effects: Common adverse reactions include hypotension, bradycardia, AV block, and liver function abnormalities 2
• Long-term Amiodarone Toxicity: About 51% of patients experience adverse effects including tremor/ataxia, nausea, visual disturbances, thyroid abnormalities, and pulmonary infiltrates 4
• Bretylium Effects: Initially causes norepinephrine release (potential hypertension) followed by hypotension; continue CPR for at least 20 minutes after administration 1