Restoration of a palpable pulse documented during resuscitation. A case where ROSC was achieved and later lost is still counted ROSC-positive for field outcome.

Ventricular Fibrillation or pulseless Ventricular Tachycardia as the first monitored rhythm. These are defibrillation-eligible and generally carry a better prognosis; the shockable-to-ROSC rate is the key Utstein survival signal.

Patient documented with ROSC in the Field or ROSC in the ED — arrived at the receiving facility with a pulse. Re-arrest = achieved ROSC but did not survive to hospital.

CPR initiated before the transporting EMS unit arrived — bystander, family, law enforcement, or a non-transporting first responder. Transport-EMS listed as the initiator is treated as a likely documentation error.

STEMI criteria on a 12-lead obtained more than 7 minutes after ROSC in the rhythm stream, indicating possible acute coronary occlusion warranting cath-lab activation.

A record counts as documented when the resuscitation-efforts field carries a real value (an attempted effort, or "Not Applicable"). "Not Recorded" and blank fields are reported separately as a gap.

Any affirmative pre-arrival alert counts toward the alert rate. An alert documented as a NON-cardiac type (e.g. Yes-STEMI on an arrest) is counted but flagged as a documentation mismatch for review.

Dispatch notification to the FASTER of unit-on-scene or first-responder-on-scene, so a non-transporting engine arriving first is credited.