The primary objective of this pilot, pragmatic stepped-wedge cluster randomized trial is to evaluate if a modified cardiac arrest treatment algorithm calling for the administration of the initial amiodarone dose one 2-minute cycle earlier than current guidelines (during the same cycle as the initial dose of epinephrine) improves the time to amiodarone delivery in those with out-of-hospital cardiac arrest due to refractory ventricular fibrillation or ventricular tachycardia compared to usual care.