What is the management approach for ventricular tachycardia (VT)?

Management of Ventricular Tachycardia

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

Initial Assessment and Management

Hemodynamically Unstable VT

1. Immediate synchronized cardioversion

   • Perform without delay for patients with hypotension, altered mental status, shock, or acute heart failure
   • Sedate if conscious and time permits
   • Initial energy: maximum output (typically 200J biphasic)
   • Place defibrillator patches at least 8 cm from ICD generator if present 2

2. Post-cardioversion care

   • Monitor for recurrence
   • Correct electrolyte and acid-base disturbances
   • Consider maintenance antiarrhythmic therapy for 6-24 hours 2

Hemodynamically Stable VT

Monomorphic VT

1. First-line pharmacological options:

   • Without severe HF or acute MI: Procainamide 10 mg/kg IV at 50-100 mg/min over 10-20 minutes 2, 3
   • With severe HF or acute MI: Amiodarone 150 mg IV over 10 minutes, followed by 1 mg/min for 6 hours, then 0.5 mg/min 2, 4

2. If first-line therapy fails:

   • Proceed to synchronized cardioversion 1
   • Consider alternative antiarrhythmic drugs:
     • Lidocaine (less effective but may be considered in suspected ischemia) 2

Polymorphic VT

1. With long QT (Torsades de Pointes):

   • IV magnesium sulfate
   • Overdrive pacing
   • Consider β-blockers 2

2. Without long QT:

   • Treat as ventricular fibrillation with unsynchronized high-energy shock if unstable
   • Correct underlying ischemia or electrolyte abnormalities

Long-term Management

Diagnostic Evaluation

• Comprehensive cardiac evaluation including:
  • 12-lead ECG
  • Echocardiography
  • Coronary assessment
  • Electrolyte panel
  • Cardiac biomarkers 2

Definitive Treatment Options

1. Catheter Ablation:

   • Urgent ablation recommended for patients with scar-related heart disease presenting with incessant VT or electrical storm 1
   • Consider after first episode of sustained VT in patients with ischemic heart disease 1

2. Implantable Cardioverter Defibrillator (ICD):

   • Consider ICD implantation, as even "stable" VT is associated with high mortality 5
   • Particularly important in patients with structural heart disease

3. Antiarrhythmic Medications:

   • β-blockers to inhibit increased sympathetic tone and prevent ischemia
   • Consider maintenance therapy with amiodarone or other antiarrhythmics based on underlying cardiac condition

Special Considerations

• VT during acute MI: Higher mortality risk; requires aggressive management of both the arrhythmia and the underlying ischemia 6
• Idiopathic VT: May respond well to calcium channel blockers or β-blockers
• Incessant VT: May lead to hemodynamic and metabolic decompensation; early resumption of normal ventricular activation is warranted 7

Pitfalls and Caveats

• Do not delay cardioversion in unstable patients
• Avoid amiodarone infusions at concentrations >2 mg/mL unless using a central venous catheter due to risk of phlebitis 4
• Rapid amiodarone infusion at high concentrations can cause hepatocellular necrosis and acute renal failure 4
• Do not assume "stable" VT is benign; mortality in stable VT can be as high or higher than in unstable VT 5
• Adenosine is not recommended for wide-complex tachycardias suspected to be VT, as it may precipitate deterioration

Remember that early definitive management with catheter ablation should be considered in all patients with recurrent VT, as it can significantly reduce future episodes and improve quality of life.