What is the treatment for ventricular tachycardia?

Treatment 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 Algorithm

Hemodynamically Unstable VT

1. Immediate direct current cardioversion (Class I recommendation) 1

   • Provide sedation first if patient is conscious but hypotensive
   • Use maximum output initially for defibrillation

2. If VT is refractory to electrical cardioversion:

   • Amiodarone: 300 mg IV over 15 minutes, may repeat after one hour 1
   • Consider magnesium (8 mmol bolus followed by 2.5 mmol/h infusion) particularly in the setting of acute myocardial infarction 1

Hemodynamically Stable VT

1. First-line pharmacological therapy options:

   • Procainamide: 10 mg/kg IV (superior to lidocaine for terminating stable monomorphic VT) 1, 2
   • Amiodarone: 150-300 mg IV over one hour 1, 3

2. If first-line therapy fails:

   • Proceed to synchronized electrical cardioversion (with appropriate sedation) 1

3. For specific VT types:

   • For LV fascicular VT (RBBB morphology with left axis deviation): IV verapamil or beta-blockers 1

Long-Term Management

1. Catheter ablation (Class I recommendation) for:

   • Patients with scar-related heart disease presenting with incessant VT or electrical storm 1
   • Patients with ischemic heart disease and recurrent ICD shocks due to sustained VT 1
   • Consider after first episode of sustained VT in patients with ischemic heart disease and an ICD 1

2. Implantable cardioverter-defibrillator (ICD) for:

   • Patients with structural heart disease and sustained symptomatic VT 4
   • Even "stable" VT is associated with high mortality and may warrant ICD placement 5

Special Considerations

Polymorphic VT

• Often associated with acute myocardial ischemia, channelopathies, or ventricular hypertrophy
• In drug-refractory cases, Purkinje-fiber triggered polymorphic VT may be amenable to catheter ablation 1

Electrical Storm

• Urgent catheter ablation is recommended 1
• Consider sympathetic blockade (including β-blockers) which may reduce recurrent and refractory ventricular arrhythmias 1

Common Pitfalls and Caveats

1. Do not delay cardioversion in hemodynamically unstable patients by attempting drug therapy first 1

2. Lidocaine limitations: Less effective than procainamide, sotalol, and amiodarone for terminating VT 1

3. Amiodarone considerations:

   • Antiarrhythmic effect may take up to 30 minutes to manifest 1
   • Associated with side effects, primarily hypotension 1
   • FDA-approved specifically for VT/VF refractory to other therapy 3

4. Procainamide caution:

   • Avoid in patients with severe congestive heart failure or acute myocardial infarction 1
   • Has potential to produce serious hematological disorders 2

5. Even stable VT requires aggressive treatment as it is associated with high mortality rates and may be a marker for a substrate capable of producing more malignant arrhythmias 5, 6

Remember that the presence of acute myocardial infarction significantly increases the risk of hemodynamic instability and death in patients with VT 6, requiring more aggressive monitoring and treatment.