Acute cardiac care & resuscitation

Association Between Delay to First Shock and Successful First-Shock Ventricular Fibrillation Termination in Patients With Witnessed Out-of-Hospital Cardiac Arrest

CirculationPublished Prospective registry cohort study

Corrected 23 Oct 2026: Measure wording clarified; no values changed.

Main finding · VF termination by delay to first shockResult — go to the resultAdjusted relative risk for failure to terminate VF 1.06 95% CI 1.04–1.07

Authors' conclusion

Every minute of delay to first shock was associated with a significantly lower proportion of VF termination and return of organized rhythm.

Study context

Population
Patients with witnessed OHCA and ventricular fibrillation (VF) as initial rhythm (ARREST registry, Amsterdam)
Participants
3,723 patients
Exposure
Longer vs shorter delay from emergency call to first shock
Outcome
VF termination at 5 seconds after the first shock, return of organized rhythm and survival to discharge, in relation to delay to first shock
Methodological detailsARREST registry, Poisson regression with robust standard errors
  • ARREST registry
  • Poisson regression with robust standard errors

Main finding

VF termination by delay to first shock · 5 seconds after first shock

Adjusted relative risk for failure to terminate VF

1.06

95% CI 1.04–1.07

Per additional minute in VF from emergency call
adjusted relative risk for failure to terminate VF 1.06 (95% CI 1.04–1.07)

Per additional minute in VF from emergency call, as printed

As reported in the abstract

VF termination with delay to first shock <6 minutes
93%
VF termination with delay to first shock >16 minutes
75%
Trend in VF termination across delay
P for trend < 0.001

Observational data: associations, not effects.

Further findings

OutcomeEstimate
Return of organized rhythmadjusted RR 0.96 (95% CI 0.95–0.98)
Survival to dischargeadjusted relative risk for surviving to discharge 0.94 (95% CI 0.93–0.95)

Original publication

Association Between Delay to First Shock and Successful First-Shock Ventricular Fibrillation Termination in Patients With Witnessed Out-of-Hospital Cardiac Arrest. Circulation. Published 27 October 2024. doi:10.1161/circulationaha.124.069834

Composed by AI from the published abstract and checked against it. How Briefs are made →

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