From the Guidelines
Amiodarone should be administered in pulseless ventricular tachycardia (VT) as a second-line antiarrhythmic medication after defibrillation attempts have failed to restore a normal rhythm, with a recommended dose of 300 mg IV push for the first dose, followed by a second dose of 150 mg if needed, as supported by the 2018 American Heart Association guidelines 1. The use of amiodarone in this context is based on its ability to block multiple ion channels (sodium, potassium, and calcium) and its alpha and beta-adrenergic blocking properties, which help stabilize cardiac cell membranes and suppress the abnormal electrical activity driving VT. Key points to consider when administering amiodarone in pulseless VT include:
- Defibrillation and high-quality CPR remain the primary interventions for pulseless VT, with amiodarone administered only after initial defibrillation attempts and while continuing CPR 1.
- Amiodarone should be pushed rapidly through a large-bore IV or IO, followed by a saline flush.
- The medication may cause hypotension upon return of spontaneous circulation, so blood pressure monitoring is essential after resuscitation.
- Lidocaine (1-1.5 mg/kg IV) can be considered as an alternative if amiodarone is unavailable, although it has not been demonstrated to improve rates of return of spontaneous circulation (ROSC) and hospital admission compared to amiodarone 1.
From the FDA Drug Label
Amiodarone hydrochloride injection is indicated for initiation of treatment and prophylaxis of frequently recurring ventricular fibrillation (VF) and hemodynamically unstable ventricular tachycardia (VT) in patients refractory to other therapy. The answer is: to treat pulseless VTach that is refractory to other therapy 2.
- Key points:
- Amiodarone is used for initiation of treatment and prophylaxis of VTach and VF
- It is used in patients who are refractory to other therapy
- The indication is for hemodynamically unstable VTach, which includes pulseless VTach.
From the Research
Rationale for Amiodarone Use in Pulseless VTach
- Amiodarone is used in the treatment of pulseless ventricular tachycardia (VTach) due to its effectiveness in suppressing ventricular arrhythmias 3.
- The American Heart Association Advanced Cardiac Life Support (ACLS) guidelines support the use of amiodarone for cardiac arrest caused by VTach or ventricular fibrillation (VF) 4, 3.
- Studies have shown that amiodarone can improve outcomes in patients with in-hospital cardiac arrest from VT/VF, including return of spontaneous circulation (ROSC), 24-hour survival, survival to hospital discharge, and favorable neurologic outcome 4.
Comparison with Lidocaine
- Lidocaine has also been shown to be effective in the treatment of VTach, with some studies suggesting it may have a higher success rate than amiodarone in certain patient populations 4, 5.
- However, the European Resuscitation Council Guidelines for Resuscitation 2018 update suggests that the beneficial effects of amiodarone and lidocaine are similar 6.
- The choice between amiodarone and lidocaine may depend on factors such as availability, cost, and patient-specific considerations 5.
Clinical Implications
- Amiodarone requires careful preparation and delivery to achieve safe and effective outcomes 3.
- The use of antiarrhythmic drugs, including amiodarone, should be considered as part of a comprehensive approach to managing cardiac arrest, including CPR and defibrillation 5, 6.
- In patients with advanced heart failure, amiodarone may be effective in suppressing ventricular arrhythmias, but its use is associated with a substantial risk of cardiac and noncardiac adverse effects 7.