What is the pharmacological treatment for ventricular tachycardia?

Pharmacological Treatment for Ventricular Tachycardia

For ventricular tachycardia (VT), intravenous amiodarone combined with beta-blockers is the recommended first-line pharmacological treatment for hemodynamically stable patients, while immediate synchronized DC cardioversion is indicated for unstable VT. 1, 2

Initial Assessment and Management

• First determine if the patient has a pulse and assess hemodynamic stability, checking for adverse signs such as low blood pressure, chest pain, heart failure, or high heart rate 3
• For unstable VT with pulse, perform immediate synchronized DC cardioversion (100J, 200J, 360J) with sedation if the patient is conscious 1, 2

Pharmacological Management for Hemodynamically Stable VT

First-Line Therapy

• Intravenous amiodarone: 150 mg over 10 minutes, followed by infusion of 1.0 mg/min for 6 hours, then maintenance at 0.5 mg/min 1, 4
• Beta-blockers should be administered concurrently with amiodarone, particularly for polymorphic VT storm 1
• The recommended starting dose of amiodarone is about 1000 mg over the first 24 hours of therapy 4

Alternative Agents

• Lidocaine: 1.0-1.5 mg/kg bolus, with supplemental boluses of 0.5-0.75 mg/kg every 5-10 minutes to maximum 3 mg/kg total loading dose, followed by infusion of 2-4 mg/min 1
  • Some guidelines suggest 50 mg IV over 2 minutes, repeated every 5 minutes to a total dose of 200 mg, followed by maintenance infusion 2, 3
• Procainamide: loading infusion of 20-30 mg/min up to 12-17 mg/kg, followed by infusion of 1-4 mg/min 1

Special Considerations

• For torsades de pointes, administer magnesium (8 mmol) if hypomagnesemia is suspected 1, 2
• Reduce lidocaine infusion rates in older patients and those with heart failure or hepatic dysfunction 1
• Reduce procainamide infusion rates in patients with renal dysfunction 1
• Amiodarone must be delivered by a volumetric infusion pump, preferably through a central venous catheter 4
• For infusions longer than 1 hour, do not exceed amiodarone concentrations of 2 mg/mL unless a central venous catheter is used 4
• In breakthrough episodes of VF or hemodynamically unstable VT, use 150 mg supplemental infusions of amiodarone (mixed in 100 mL of D5W and infused over 10 minutes) 4

FDA-Approved Indications for IV Amiodarone

• Amiodarone is indicated for initiation of treatment and prophylaxis of frequently recurring VF and hemodynamically unstable VT in patients refractory to other therapy 4
• It can also be used to treat patients with VT/VF for whom oral amiodarone is indicated but who are unable to take oral medication 4
• Most patients will require therapy for 48 to 96 hours, but amiodarone may be safely administered for longer periods if necessary 4

Long-Term Management Considerations

• For long-term management, sotalol has shown high efficacy in both inducible and non-inducible VT 5
• Patients with inducible VT not responding to sotalol are likely to be refractory to other antiarrhythmic drugs and should be considered for non-pharmacological therapy 5
• Beta-blockers are recommended for primary prevention of sudden cardiac death 6
• Implantable cardioverter-defibrillator has proven to improve prognosis for secondary prevention 6

Common Pitfalls and Caveats

• Intravenous amiodarone loading infusions at higher concentrations and rates than recommended have resulted in hepatocellular necrosis and acute renal failure, leading to death 4
• Most antiarrhythmic drugs depress myocardial contractility and require careful monitoring, especially in hemodynamically compromised patients 2
• Class IC antiarrhythmic drugs like flecainide should be used with caution due to potential proarrhythmic effects, especially in patients with structural heart disease 7
• When a particular drug does not terminate tachycardia, further drugs should not be given; electrical cardioversion is preferred 7