What is the treatment for ventricular tachycardia?

Treatment of Ventricular Tachycardia

The treatment of ventricular tachycardia (VT) requires immediate assessment of hemodynamic stability, with unstable VT requiring urgent synchronized electrical cardioversion at 100J for monomorphic VT or unsynchronized shock at 200J for polymorphic VT, while stable VT can be treated with antiarrhythmic medications, with procainamide being the first-line drug of choice. 1

Initial Assessment and Management

Hemodynamically Unstable VT

• Immediate synchronized cardioversion (100J biphasic or 200J monophasic) 1
• Provide sedation if patient is conscious and time permits
• For pulseless VT, follow VF protocol with high-quality CPR and defibrillation 2
• If no venous access, medications (particularly epinephrine) may be delivered via endotracheal route in double or triple doses 2

Hemodynamically Stable VT

1. First-line pharmacological therapy:

   • Procainamide: Loading infusion 20-30 mg/min up to 12-17 mg/kg, followed by 1-4 mg/min maintenance infusion 1, 3
   • FDA-approved for treatment of documented ventricular arrhythmias that are life-threatening 3

2. Alternative medications:

   • Lidocaine (Lignocaine): 1-1.5 mg/kg IV bolus (50 mg over 2 min, repeated every 5 min to total dose of 200 mg), followed by infusion of 2-4 mg/min 2, 1
     • Particularly useful when VT is associated with acute myocardial ischemia/infarction 1
   • Amiodarone: 150 mg IV over 10 minutes, followed by 1 mg/min for 6 hours, then 0.5 mg/min 1, 4
     • FDA-approved for VT refractory to other therapy 4
   • Magnesium: 8 mmol bolus followed by 2.5 mmol/h infusion (particularly effective when VT is associated with acute myocardial infarction) 2

3. If pharmacological therapy fails:

   • Proceed to synchronized cardioversion (100J, 200J, 360J) 2, 1
   • Consider transvenous catheter pace termination for recurrent VT 1

Special Considerations

VT Type-Specific Management

• Polymorphic VT: Consider beta-blockers (especially if ischemia is suspected) and urgent angiography if myocardial ischemia cannot be excluded 1
• Torsades de Pointes: Stop QT-prolonging medications, correct electrolyte abnormalities, administer IV magnesium, consider pacing or isoproterenol if bradycardia is present 1

Important Cautions

• Always presume wide-QRS tachycardia to be VT if diagnosis is unclear 1
• Avoid calcium channel blockers (verapamil, diltiazem) for wide-complex tachycardias of unknown origin 1
• Procainamide has potential to produce serious hematological disorders (0.5%), particularly leukopenia or agranulocytosis (sometimes fatal) 3

Long-Term Management

Implantable Cardioverter-Defibrillator (ICD)

• Recommended for prevention of sudden cardiac death in patients with documented sustained VT who are receiving optimal medical therapy 1
• Patients with fast VT (cycle length ≤250 ms) are at higher risk for recurrence and may benefit most from ICD therapy 1

Catheter Ablation

• Cornerstone of treatment for scar-related VT 1
• Acute success rates range from 41-81%, with freedom from VT at 6 months ranging from 46-53% 1
• Potential complications include damage to coronary vasculature, inadvertent puncture of surrounding organs, left phrenic nerve palsy, and pericardial tamponade 1

Surgical Options

• Reserved for cases where standard drugs and percutaneous ablation fail 5
• Employs electroanatomic mapping and various ablation strategies and technologies 5

Follow-up Management

• Initiate oral beta-blockers for long-term follow-up 1
• Regular monitoring for VT recurrence 1
• VT recurrence rates remain significant: 24-26% at 1 year and 50-55% at 4 years 1

Remember that the approach to VT management should be guided by the patient's hemodynamic stability, with immediate electrical cardioversion for unstable patients and a more measured pharmacological approach for stable patients, followed by appropriate long-term management strategies.