What is the management of pulseless ventricular tachycardia (VT) post-cardiac arrest?

From the Guidelines

The management of pulseless ventricular tachycardia (VT) post-cardiac arrest should prioritize the administration of amiodarone or lidocaine, as these antiarrhythmic drugs may be considered for VF/pVT that is unresponsive to defibrillation, according to the 2018 American Heart Association guidelines 1. The goal of management is to prevent recurrence and address underlying causes, with immediate interventions including antiarrhythmic medication administration.

• Key considerations include:
  • Administering amiodarone 300 mg IV bolus, followed by 150 mg IV after 3-5 minutes if needed, then a maintenance infusion of 1 mg/min for 6 hours and 0.5 mg/min thereafter
  • Using lidocaine as an alternative at 1-1.5 mg/kg IV bolus, followed by 0.5-0.75 mg/kg every 5-10 minutes (maximum 3 doses), then an infusion of 1-4 mg/min
  • Correcting electrolyte abnormalities, particularly maintaining potassium above 4.0 mEq/L and magnesium above 2.0 mg/dL
• Post-arrest care is crucial and includes:
  • Targeted temperature management (33-36°C for 24 hours)
  • Maintaining mean arterial pressure above 65 mmHg
  • Ensuring adequate oxygenation
  • Correcting acidosis
• Once stabilized, patients require comprehensive cardiac evaluation, including:
  • Echocardiography
  • Cardiac catheterization if indicated
  • Consideration for implantable cardioverter-defibrillator placement, as supported by the guidelines 1.

From the FDA Drug Label

The acute effectiveness of intravenous amiodarone in suppressing recurrent VF or hemodynamically unstable VT is supported by two randomized, parallel, dose-response studies of approximately 300 patients each In the event of 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 to minimize the potential for hypotension)

The management of pulseless ventricular tachycardia (VT) post-cardiac arrest involves the use of intravenous amiodarone. The recommended dose is a loading infusion of about 1000 mg over the first 24 hours, followed by a maintenance infusion rate of 0.5 mg/min (720 mg per 24 hours) 2. In the event of breakthrough episodes of VF or hemodynamically unstable VT, supplemental infusions of 150 mg amiodarone can be administered over 10 minutes 2.

• Key points:
  • Intravenous amiodarone is used to suppress recurrent VF or hemodynamically unstable VT
  • Loading infusion: about 1000 mg over the first 24 hours
  • Maintenance infusion: 0.5 mg/min (720 mg per 24 hours)
  • Supplemental infusions: 150 mg over 10 minutes for breakthrough episodes of VF or hemodynamically unstable VT 2, 2

From the Research

Management of Pulseless Ventricular Tachycardia (VT) Post-Cardiac Arrest

The management of pulseless VT post-cardiac arrest involves several key steps, including:

• High-quality cardiopulmonary resuscitation (CPR) with minimal interruptions, as emphasized in 3
• Prompt defibrillation, with the optimal timing of defibrillation shocks being shortly after the peak of the QRS complex, as found in 4
• The use of antiarrhythmic drugs, such as amiodarone or lidocaine, although the benefit of these drugs appears to be limited to patients in whom initial early CPR and defibrillation attempts fail, as discussed in 5
• Consideration of alternative treatments, such as percutaneous coronary intervention, extra-corporeal CPR, and emerging therapies like beta-blocker therapy, dual simultaneous external defibrillation, stellate ganglion blockade, and extracorporeal cardiopulmonary resuscitation, as reviewed in 6

Antiarrhythmic Drug Therapy

The use of antiarrhythmic drugs in the treatment of pulseless VT is a topic of ongoing debate, with some studies suggesting that these drugs may improve survival rates, particularly in patients with witnessed arrest, as reported in 5. However, other studies have found no clear survival benefit for any one particular drug, and factors such as availability and cost should be considered when deciding which drug to use, as noted in 5. Amiodarone, in particular, has been shown to be a highly efficacious antiarrhythmic agent for many cardiac arrhythmias, including ventricular tachyarrhythmias, as discussed in 7.

Defibrillation Techniques

The technique of defibrillation is also an important consideration in the management of pulseless VT, with some studies suggesting that dual simultaneous external defibrillation may be more effective than traditional defibrillation methods, as reviewed in 6. Additionally, the timing of defibrillation shocks is critical, with shocks delivered shortly after the peak of the QRS complex appearing to offer significant advantages over shocks delivered at other parts of the cardiac cycle, as found in 4.