Background Pulseless electrical activity (PEA) is increasingly observed in out-of-hospital cardiac arrest (OHCA), but outcomes are still poor. We aimed to assess the relationship between QRS characteristics and outcomes of patients with OHCA with initial PEA (OHCA-P).
Methods This prospective observational study included patients aged at least 18 years who developed OHCA-P between 1 January 2016 and 31 December 2018, and were enrolled in the Daegu Emergency Medical Services registry, South Korea. We performed multivariable logistic regression analyses to identify the associations between QRS characteristics and OHCA-P outcomes, in which QRS complexes were considered separately (model 1) and simultaneously (model 2). The primary outcome was survival to hospital discharge and the secondary outcome was a favourable neurological outcome.
Results Of the 3659 patients with OHCA, 576 were enrolled (median age 73 years; 334 men). A higher QRS amplitude was associated with survival to hospital discharge and a favourable neurological outcome in model 1 (adjusted OR (aOR) 1.077 and 1.106, respectively; 95% CI 1.021 to 0.136 and 1.029 to 1.190, respectively) and model 2 (aOR 1.084 and 1.123, respectively; 95% CI 1.026 to 1.145 and 1.036 to 1.216, respectively). A QRS width of <120 ms was associated with survival to hospital discharge and a favourable neurological outcome in model 1 (aOR 3.371 and 4.634, respectively; 95% CI 1.633 to 6.960 and 1.562 to 13.144, respectively) and model 2 (aOR 3.213 and 5.103, respectively; 95% CI 1.568 to 6.584 and 1.682 to 15.482, respectively). Survival to hospital discharge and neurological outcome were not associated with QRS frequency.
Conclusion OHCA-P outcomes were better when the initial QRS complex showed a higher amplitude or narrower width.
- cardiac arrest
- prehospital care
Statistics from Altmetric.com
Handling editor Edward Carlton
Contributors HWR, as chief investigator and corresponding author, organised the collaborative research team, developed the study methodology, collected and analysed the data, supervised the whole study, and reviewed and edited the final draft. JHK, as first author, conceptualised the study, performed the data curation and formal analysis, and drafted and revised the manuscript. J-YK was in charge of the statistical analysis plan, supervised the statistical analyses and redrafted the manuscript. JYA, SM, DEL, YHM and JWS contributed to the study design, proposals, investigation, validation and redrafting of the manuscript. All authors had full access to all of the study data and take responsibility for the integrity and accuracy of the data.
Funding This work was supported by a 2019 Yeungnam University Research Grant (No 219A580069).
Competing interests None declared.
Patient and public involvement Patients and/or the public were not involved in the design, or conduct, or reporting, or dissemination plans of this research.
Patient consent for publication Not required.
Ethics approval Data collection started after approval was obtained from the institutional review board of each participating hospital.
Provenance and peer review Not commissioned; externally peer reviewed.
Data availability statement No data are available. We do not have permission to share the data on this project.
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.