What would you order to convert a patient with runs of ventricular tachycardia (VTach) back to a normal sinus rhythm?

Management of Ventricular Tachycardia

First-Line Treatment for Runs of VTach

For a patient with runs of ventricular tachycardia, amiodarone 150 mg IV over 10 minutes is the recommended first-line medication for conversion to normal sinus rhythm, followed by a maintenance infusion of 1 mg/min for 6 hours, then 0.5 mg/min thereafter. 1

Hemodynamic Status Assessment

The initial approach depends on hemodynamic stability:

• Unstable patient (hypotension, chest pain, altered mental status, signs of shock):

  • Immediate synchronized cardioversion at 100J (biphasic) or 200J (monophasic) 2
  • Prepare for possible defibrillation if rhythm deteriorates to VF

• Stable patient:

  • Proceed with pharmacological management

Pharmacological Management

First-Line Agent:

• Amiodarone IV:
  • Initial dose: 150 mg IV over 10 minutes
  • Follow with: 1 mg/min infusion for 6 hours
  • Then: 0.5 mg/min thereafter 2, 1
  • Parameters for administration: Runs of VTach that are sustained (>30 seconds) or symptomatic
  • Maximum daily dose: 2.2g IV per 24 hours 2

Alternative Agents (if amiodarone contraindicated):

1. Procainamide:

   • Dose: 10 mg/kg IV at rate of 20-50 mg/min
   • Particularly effective for hemodynamically stable monomorphic VT without severe heart failure or acute MI 2
   • Stop infusion if: hypotension occurs, QRS widens >50%, or arrhythmia terminates

2. Lidocaine:

   • Dose: 1-1.5 mg/kg IV bolus
   • Maintenance: 1-4 mg/min (30-50 mcg/kg/min)
   • Note: Less effective than procainamide, amiodarone, or sotalol 2

3. Sotalol:

   • May be considered for stable monomorphic VT, including in patients with acute MI 2

Parameters for Medication Administration

Monitor for:

1. Hemodynamic parameters:

   • Blood pressure: Hold or slow infusion if systolic BP <90 mmHg
   • Heart rate: Monitor for bradycardia (hold if HR <50 bpm)

2. ECG monitoring:

   • QT interval: Hold amiodarone if QTc >500 ms
   • QRS duration: Hold procainamide if QRS widens >50% from baseline

3. Respiratory status:

   • Monitor for respiratory depression, especially with sedation for cardioversion

Special Considerations

For Polymorphic VT (Torsades de Pointes):

• If associated with long QT: Magnesium sulfate 2g IV over 5-60 minutes 2
• Consider overdrive pacing if recurrent episodes 2

For VT Storm (recurrent episodes):

• Beta-blockers may improve outcomes in refractory cases 2
• Consider deeper sedation and mechanical ventilation if episodes continue

Monitoring After Conversion

After successful conversion to sinus rhythm:

• Continue cardiac monitoring for at least 24 hours
• Obtain electrolyte panel and correct any abnormalities
• Consider echocardiogram to assess structural heart disease
• Cardiology consultation for long-term management

Common Pitfalls to Avoid

1. Misdiagnosis: Ensure the rhythm is truly VT and not SVT with aberrancy
2. Delayed cardioversion in unstable patients - electrical cardioversion should not be delayed for medication administration in hemodynamically compromised patients
3. Medication interactions: Amiodarone interacts with many drugs including warfarin, digoxin, and other antiarrhythmics
4. Overlooking underlying causes: Always investigate and treat potential triggers (ischemia, electrolyte abnormalities, drug toxicity)
5. Inadequate monitoring: Continuous cardiac monitoring is essential during and after treatment

By following this algorithm, you can effectively manage patients with runs of ventricular tachycardia while minimizing risks and optimizing outcomes.