What are the medications for treating ventricular tachycardia (VTach) storm?

Medications for VTach Storm

Amiodarone is the first-line medication for ventricular tachycardia storm, with an initial loading dose of 150 mg IV over 10 minutes, followed by 1 mg/min for 6 hours, then 0.5 mg/min maintenance. 1, 2

First-Line Pharmacological Management

Amiodarone

• Initial dose: 150 mg IV over 10 minutes
• Follow with: 1 mg/min infusion for 6 hours
• Maintenance: 0.5 mg/min (720 mg/24 hours) 1, 2
• For breakthrough episodes: Additional 150 mg supplemental infusions over 10 minutes 2
• FDA-approved specifically for hemodynamically unstable VT refractory to other therapy 2
• Efficacy: 63-78% response rate in patients with recurrent, refractory VT 3, 4

Beta-Blockers

• Particularly effective for polymorphic VT storm 1
• Metoprolol: 5 mg IV over 1-2 minutes, repeated as needed every 5 minutes to maximum 15 mg 5
• Esmolol: Loading dose 500 mcg/kg over 1 minute, followed by infusion of 50 mcg/kg/min; can increase to maximum 300 mcg/kg/min 5
• Essential for catecholaminergic polymorphic VT and VT associated with acute ischemia 5, 1

Second-Line Medications

Lidocaine

• Particularly useful for ischemia-related VT 1
• Dosing: 1.0-1.5 mg/kg IV bolus, supplemental boluses of 0.5-0.75 mg/kg every 5-10 minutes
• Maintenance: 2-4 mg/min infusion 1
• Less effective than amiodarone (27% vs 78% immediate termination rate) 4

Procainamide

• Dosing: 20-50 mg/min until arrhythmia suppressed, hypotension occurs, QRS prolongs by 50%, or total dose of 17 mg/kg reached 5, 1
• Alternative: 100 mg every 5 minutes until arrhythmia controlled 5
• Caution: Avoid in patients with QT prolongation and heart failure 5
• Monitor for hypotension and QT prolongation 1

Magnesium Sulfate

• Particularly effective for torsades de pointes
• Dosing: 8 mmol bolus followed by infusion 1
• Consider for all forms of polymorphic VT

Special Considerations

For Specific VT Types:

• Polymorphic VT/Torsades de Pointes:

  • Magnesium sulfate: First-line
  • Beta-blockers: For catecholaminergic polymorphic VT
  • Isoproterenol: For pause-dependent torsades (if no congenital LQTS) 1
  • Potassium repletion to 4.5-5 mmol/L 1

• Ischemia-related VT:

  • Lidocaine: Preferred for acute ischemic settings
  • Urgent coronary revascularization when appropriate

• Incessant VT/Electrical Storm:

  • Amiodarone + beta-blocker combination
  • Deep sedation may be necessary to reduce sympathetic tone
  • Consider urgent catheter ablation if medication fails 1

Monitoring During Treatment

• Continuous cardiac monitoring is essential
• Regular blood pressure assessment
• Monitor for drug toxicity:
  • Amiodarone: Hypotension, bradycardia, phlebitis 5, 2
  • Procainamide: QT prolongation, hypotension 5, 1
  • Lidocaine: CNS toxicity at high doses

Important Cautions

• Avoid calcium channel blockers for wide-complex tachycardias of unknown origin 1
• Do not combine multiple AV nodal blocking agents with longer duration of action 1
• Class IC antiarrhythmic drugs should not be used in patients with history of MI 1
• Amiodarone concentrations >2 mg/mL should be administered via central venous catheter to avoid phlebitis 2
• High-dose IV amiodarone can cause serious adverse events including hypotension (23%) and bradycardia (11%) 3

For VTach storm that is truly refractory to medical therapy, urgent catheter ablation is recommended as a definitive treatment, particularly for patients with scar-related heart disease 1.