What is the management of Ventricular Tachycardia (VT)?

Management of Ventricular Tachycardia

Immediate Assessment and Stabilization

For any patient presenting with VT, immediately assess hemodynamic stability—if the patient is hypotensive, has altered mental status, or shows signs of shock, proceed directly to synchronized cardioversion without delay. 1, 2

Hemodynamically Unstable VT

• Perform immediate synchronized direct current cardioversion for patients with hemodynamic compromise 1, 2
• If the patient is hypotensive but conscious, provide immediate sedation before cardioversion 2
• Use 100 J synchronized discharge for monomorphic VT with rates >150 bpm 2
• Use unsynchronized 200 J discharge for polymorphic VT that resembles ventricular fibrillation 2
• Wide-QRS tachycardia should be presumed to be VT if the diagnosis is unclear—when in doubt, treat as VT 1, 2

Hemodynamically Stable VT

For stable patients, confirm the diagnosis using ECG criteria before initiating treatment, but maintain a low threshold for cardioversion if any clinical deterioration occurs. 2

Diagnostic ECG Criteria to Confirm VT:

• QRS width >0.14 seconds with RBBB pattern or >0.16 seconds with LBBB pattern 1, 2
• AV dissociation (independent P waves) 1
• Fusion or capture beats (diagnostic of VT) 1
• RS interval >100 ms in any precordial lead 1
• Negative concordance in precordial leads (all QS complexes) is diagnostic for VT 1
• QR complexes indicate myocardial scar and are present in ~40% of post-MI VT 1

Pharmacological Management of Stable Monomorphic VT

Intravenous procainamide is the preferred first-line agent for stable monomorphic VT when early termination is desired, as it demonstrates the greatest efficacy for rhythm conversion. 1, 3

First-Line: Procainamide

• Administer 10 mg/kg IV at 50-100 mg/min over 10-20 minutes 3
• Monitor blood pressure and ECG continuously during infusion 1, 3
• Particularly appropriate when early slowing of VT rate and termination are desired 1
• Close monitoring required in patients with congestive heart failure or severe transient hypotension 1

Alternative Agents:

Intravenous amiodarone (Class IIa):

• Reasonable for sustained monomorphic VT that is hemodynamically unstable, refractory to cardioversion, or recurrent despite procainamide 1
• Preferred in patients with heart failure or suspected myocardial ischemia 2
• Loading dose: approximately 1000 mg over first 24 hours (150 mg over 10 minutes, then 1 mg/min for 6 hours, then 0.5 mg/min) 4
• Not ideal for early conversion of stable monomorphic VT 1
• Supplemental 150 mg boluses (over 10 minutes) for breakthrough VT episodes 4

Intravenous lidocaine (Class IIb):

• May be reasonable specifically for VT associated with acute myocardial ischemia or infarction 1
• Effective when VT is thought to be related to myocardial ischemia 1

Critical Contraindications:

Never administer calcium channel blockers (verapamil or diltiazem) for wide-complex tachycardia of unknown origin or in patients with structural heart disease—this can precipitate hemodynamic collapse or ventricular fibrillation. 1, 2

Management of Polymorphic VT

Polymorphic VT requires urgent electrical cardioversion if hemodynamically compromised, and immediate assessment for myocardial ischemia as the underlying cause. 1

• Direct current cardioversion is first-line for hemodynamically compromised patients 1
• Intravenous beta blockers are useful for recurrent polymorphic VT, especially if ischemia is suspected or cannot be excluded 1
• Intravenous amiodarone loading is useful for recurrent polymorphic VT in the absence of QT prolongation 1
• Urgent angiography with revascularization should be considered when myocardial ischemia cannot be excluded 1
• Intravenous lidocaine may be reasonable specifically for polymorphic VT associated with acute MI 1

Post-Cardioversion Management

If VT recurs after cardioversion, initiate antiarrhythmic drug therapy immediately to prevent acute reinitiation. 2

• Correct potentially causative conditions: hypokalemia, hypomagnesemia, and ongoing ischemia 1
• Most post-MI VT/VF occurs within first 48 hours; sustained VT/VF outside this window requires careful evaluation including consideration of electrophysiology studies 2
• Continue maintenance amiodarone infusion at 0.5 mg/min for 2-3 weeks if needed 4

Advanced Interventions

Transvenous Pacing

• Catheter pace termination can be useful for sustained monomorphic VT refractory to cardioversion or frequently recurrent despite antiarrhythmic medications 1

Urgent Catheter Ablation

The European Society of Cardiology recommends urgent catheter ablation for patients with scar-related heart disease presenting with incessant VT or electrical storm. 2

• Consider catheter ablation in ischemic heart disease patients with recurrent ICD shocks due to sustained VT 2
• May be considered after first episode of sustained VT in ischemic heart disease patients with an ICD 2
• Should be performed at experienced centers, particularly for patients with structural heart disease 5

Special Clinical Contexts

VT in Acute Coronary Syndrome

• VT occurring early in ACS is associated with increased hospital mortality 1
• Correction of ischemia is an early priority 1
• Beta blockers improve mortality in recurrent polymorphic VT with acute MI 1
• Consider urgent revascularization for polymorphic VT when ischemia cannot be excluded 1

Electrical Storm (≥3 VT episodes in 24 hours)

• Requires accelerated management protocol 6
• Consider urgent VT transcatheter ablation with or without mechanical circulatory support in high-risk patients 6
• Intensive patient management with multispecialty team integration 5

Common Pitfalls to Avoid

• Never assume a wide-complex tachycardia is supraventricular—always treat as VT when uncertain 1, 2
• Avoid calcium channel blockers unless absolutely certain of fascicular VT diagnosis 1, 2
• Do not use drop counter infusion sets for amiodarone—they can underdose by up to 30%; always use volumetric infusion pumps 4
• Amiodarone concentrations >2 mg/mL require central venous access to avoid peripheral vein phlebitis 4
• Most patients require acute amiodarone therapy for 48-96 hours for ventricular arrhythmia stabilization 4