Early Defibrillation for Ventricular Fibrillation Cardiac Arrest in the Emergency Department; Systematic Review

Background: Ventricular fibrillation (VF) and pulseless ventricular tachycardia (pVT) are time sensitive cardiac arrest rhythms where survival depends on rapid defibrillation. In the emergency department (ED), both out of hospital cardiac arrest (OHCA) arrivals and in ED and in-hospital cardiac arrest (IHCA) events may be encountered. The ED specific evidence base on early defibrillation is limited in ED cohorts and broader in hospital registries. Objective: our study aim to analyze original articles from PubMed Central on the association between early defibrillation and outcomes in VF and pVT cardiac arrest managed in ED settings. Methods: We followed PRISMA methods, structured question, reproducible search strategy, eligibility criteria, dual stage screening, standardized extraction, and narrative synthesis. We searched electronic databases for full-text on December 2026 for studies reporting VF and pVT arrests with a measurable defibrillation time variable (time to first shock, defibrillation within 2 minutes, or rhythm analysis before arrest team arrival). We included original human studies and excluded reviews, editorials, simulations, and single patient case reports. Results: Ten original studies met inclusion criteria, in ED-managed arrests, time to first defibrillation differ widely (median 2 to 3 minutes in one ED cohort with survivors vs non-survivors showing similar times, and 10 to 12 minutes in shockable cases in another ED based study). In a large adult IHCA registry analysis, defibrillation within 2 minutes was associated with better longer term survival reported as a 49% higher likelihood of 1 year survival. A pediatric IHCA registry analysis found no significant association between defibrillation time and survival to discharge. In Danish hospitals, rhythm analysis before cardiac arrest team arrival was associated with higher ROSC. Conclusion: our finding prioritize rapid defibrillation for VF/pVT, with strong adult in hospital registry signals favoring very early shocks (≤2 minutes), while ED-specific cohorts show variable timing and outcomes. Pediatric in-hospital data indicate that timing effects differ by age group or clinical context. Higher-quality ED-specific prospective studies were needed.