What is the immediate management for a patient presenting with ventricular tachycardia (VT)?

Immediate Management of Ventricular Tachycardia

For patients presenting with ventricular tachycardia (VT), immediate synchronized cardioversion is the first-line treatment if the patient is hemodynamically unstable. 1

Assessment of Hemodynamic Stability

• Hemodynamically unstable VT (presence of any of these signs):

  • Hypotension
  • Altered mental status
  • Signs of shock
  • Chest pain
  • Acute heart failure symptoms

• Hemodynamically stable VT:

  • Normal blood pressure
  • No symptoms of compromised perfusion

Management Algorithm

Hemodynamically Unstable VT

1. Immediate synchronized cardioversion at maximum output (with sedation if patient is conscious and time permits) 1
2. If ICD is present, place defibrillator patches at least 8 cm from the ICD generator 1
3. If VT persists or recurs after cardioversion:
   • Administer amiodarone 150 mg IV bolus over 10 minutes 2
   • Follow with maintenance infusion of 1 mg/min for 6 hours, then 0.5 mg/min thereafter 2

Hemodynamically Stable VT

1. For monomorphic VT without severe heart failure or acute MI:

   • Procainamide 10 mg/kg IV is recommended 3

2. For monomorphic VT with severe heart failure or acute MI:

   • Amiodarone is recommended 3
   • Initial load: 150 mg IV over 10 minutes
   • Follow with 1 mg/min for 6 hours, then 0.5 mg/min 2

3. For polymorphic VT with long QT (Torsades de Pointes):

   • IV magnesium
   • Overdrive pacing
   • Consider β-blockers 3

Post-Conversion Management

1. Monitor for recurrence
2. Correct any electrolyte and acid-base disturbances 3
3. Administer β-blockers to inhibit increased sympathetic tone and prevent ischemia 3
4. Consider maintenance antiarrhythmic therapy:
   • If infusion of an antiarrhythmic drug is initiated (e.g., amiodarone), maintain for 6-24 hours and then reassess need 3
5. Perform comprehensive cardiac evaluation:
   • Echocardiography
   • Coronary assessment 1
6. Consider ICD implantation, as even "stable" VT is associated with high mortality 1

Important Considerations

• Amiodarone should be delivered by a volumetric infusion pump, preferably through a central venous catheter 2
• For infusions longer than 1 hour, do not exceed amiodarone concentrations of 2 mg/mL unless using a central venous catheter 2
• Close monitoring with adjustment of dose is essential due to considerable interindividual variation in response to amiodarone 2
• Do not exceed an initial amiodarone infusion rate of 30 mg/min to avoid hypotension 2
• Intravenous amiodarone loading infusions at much higher concentrations and rates than recommended have resulted in hepatocellular necrosis and acute renal failure, leading to death 2

Prognosis

Mortality after a first episode of VT is high, with actuarial survival at 1 and 2 years being 64% and 62%, respectively 4. Severe congestive heart failure is the most powerful prognostic factor for poor outcomes 4.