What is the treatment for ventricular tachycardia (VT) storm?

Treatment of Ventricular Tachycardia Storm

For VT storm, immediate synchronized electrical cardioversion is the first-line treatment for hemodynamically unstable patients, followed by intravenous amiodarone as the most effective antiarrhythmic agent for prevention of recurrence. 1

Initial Management

Hemodynamically Unstable VT

1. Immediate synchronized DC cardioversion

   • Start with 100 J, escalate to 200 J, then 360 J if unsuccessful 1, 2
   • Provide appropriate sedation as necessary 1

2. Post-cardioversion pharmacological management

   • Intravenous amiodarone: 300 mg IV bolus over 10 minutes, followed by 1 mg/min infusion for 6 hours, then 0.5 mg/min 1
   • An additional 150 mg IV dose may be given if VT recurs 1
   • Maximum daily dose: 2100 mg (higher doses increase risk of hypotension) 3

Hemodynamically Stable VT

1. Intravenous procainamide

   • Reasonable for initial treatment of stable sustained monomorphic VT 1
   • Administer at 30 mg/min to a total dose of 17 mg/kg 1
   • Monitor blood pressure and cardiovascular status closely 1

2. Intravenous amiodarone

   • For VT that is refractory to conversion with procainamide or recurrent despite other agents 1
   • Dosing as above

Management of Refractory VT Storm

1. Beta blockers

   • Intravenous beta blockers are particularly effective for polymorphic VT 1
   • Considered the single most effective therapy for polymorphic VT storm 1

2. Combination therapy

   • Intravenous amiodarone and beta blockers together may be reasonable for VT storm 1

3. Additional interventions for refractory cases

   • Overdrive pacing may be considered 1
   • General anesthesia may be considered 1
   • Urgent coronary angiography with revascularization if ischemia is suspected 1

Special Considerations

1. Ischemia-related VT

   • Intravenous lidocaine (1-1.5 mg/kg bolus, followed by 2-4 mg/min infusion) may be reasonable for VT associated with acute myocardial ischemia 1, 2
   • Urgent revascularization should be considered when myocardial ischemia cannot be excluded 1

2. Torsades de Pointes

   • Intravenous magnesium (8 mmol bolus followed by 2.5 mmol/h infusion) 1
   • Isoproterenol for pause-dependent torsades de pointes (not for congenital long QT syndrome) 1
   • Temporary pacing for recurrent pause-dependent torsades de pointes 1

3. Electrolyte management

   • Correct hypokalemia and hypomagnesemia 1
   • Consider potassium repletion to 4.5-5 mmol/L for patients with torsades de pointes 1

Monitoring and Follow-up

1. Continuous cardiac monitoring during and after treatment 2
2. Monitor for drug toxicity:
   • Amiodarone: hypotension, bradycardia, QT prolongation, hepatotoxicity 2, 4
   • Lidocaine: CNS effects, seizures at toxic levels 1
3. Assess for underlying causes of VT including ischemia, electrolyte abnormalities, and drug toxicity 2

Important Caveats

• Avoid calcium channel blockers (verapamil, diltiazem) for wide-complex tachycardias of unknown origin, especially with history of myocardial dysfunction 1
• Amiodarone administration: Use volumetric infusion pump, preferably through a central venous catheter 3
• Concentrations >2 mg/mL should be administered via central venous access to avoid phlebitis 3
• For refractory cases resistant to conventional therapy, low-dose epinephrine (0.5-1 mg IV over 30-60 seconds) has been reported as an alternative in case reports 5

The management of VT storm requires rapid assessment and intervention, with electrical cardioversion as the cornerstone of treatment for unstable patients, followed by appropriate antiarrhythmic therapy to prevent recurrence and treat the underlying cause.