What is the immediate management for a patient with sustained ventricular (V) tachycardia?

Immediate Management of Sustained Ventricular Tachycardia

The immediate management of sustained ventricular tachycardia depends on hemodynamic stability, with urgent electrical cardioversion indicated for hemodynamically unstable VT and pharmacological therapy considered for stable VT. 1, 2

Initial Assessment and Stabilization

Hemodynamic Assessment

• Quickly determine if the patient is hemodynamically stable or unstable
• Signs of hemodynamic instability include:
  • Hypotension
  • Altered mental status
  • Signs of shock
  • Chest pain
  • Heart failure
  • Ischemia

Management Algorithm Based on Hemodynamic Status

For Hemodynamically Unstable VT:

1. Immediate synchronized cardioversion

   • Use 100J synchronized shock for monomorphic VT with rates >150 bpm 1
   • For polymorphic VT, use unsynchronized shock (defibrillation) at 200J 1, 2
   • Sedate patient if conscious and time permits 2

2. Post-cardioversion management

   • Begin antiarrhythmic therapy to prevent recurrence
   • Amiodarone: 150 mg IV over 10 minutes, followed by infusion of 1 mg/min for 6 hours, then 0.5 mg/min 1, 2, 3

For Hemodynamically Stable VT:

1. Pharmacological therapy options:

   • Procainamide (first-line): 20-30 mg/min loading infusion up to 12-17 mg/kg, followed by 1-4 mg/min infusion 1

     • Reduce infusion rates in renal dysfunction
     • Monitor for hypotension and QT prolongation

   • Amiodarone: 150 mg IV over 10 minutes, followed by 1 mg/min for 6 hours, then 0.5 mg/min 1, 3

     • Particularly useful when VT is refractory to conversion with other agents 1

   • Lidocaine: 1.0-1.5 mg/kg bolus, with supplemental boluses of 0.5-0.75 mg/kg every 5-10 minutes (maximum 3 mg/kg total loading dose) 1

     • Followed by infusion of 2-4 mg/min
     • Particularly useful when VT is associated with acute myocardial ischemia or infarction 1
     • Reduce infusion rates in older patients, CHF, or hepatic dysfunction

2. If pharmacological therapy fails:

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

Special Considerations

VT Morphology

• For polymorphic VT:
  • Consider beta-blockers, especially if ischemia is suspected 1, 2
  • Consider urgent angiography if myocardial ischemia cannot be excluded 1
  • For Torsades de Pointes: IV magnesium, correct electrolytes, consider pacing 2

Underlying Causes

• Acute myocardial infarction/ischemia is present in a significant percentage of VT cases (21% of stable VT and 65% of unstable VT) 4
• Mortality is significantly higher when VT occurs during acute MI 4

Important Caveats

• 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
• "Stable" VT is not benign - mortality rates can be high even in hemodynamically stable patients 5
• For VT occurring in the context of acute MI, early beta-blocker therapy improves mortality 1, 2
• Direct current cardioversion must be available in the emergency department, as approximately half of all VT patients may eventually require electrical therapy 4

Monitoring and Follow-up

• Close monitoring is essential during and after VT treatment
• Prepare for possible recurrence
• Consider ICD evaluation for patients with sustained VT, especially those with structural heart disease 2

By following this algorithm, clinicians can provide appropriate immediate management for patients with sustained ventricular tachycardia, prioritizing interventions that reduce morbidity and mortality.