Table 1.

Patient eligibility criteria

Inclusion criteria	Exclusion criteria
Patients are eligible for study inclusion if, • > 18 years of age • Presumed cardiac etiology • Presenting rhythm of VF/pVT • No ROSC or non-VF/pVT rhythm during first three analyses	Patients are not eligible for inclusion if, • Traumatic cardiac arrest • Pre-existing do not resuscitate orders • Non-VF/pVT presenting rhythm • Did not receive 3 consecutive defibrillation attempts • Care initiated by non-participating paramedic agency or fire service