Abstract 10855: Amplitude-Spectral Area is Associated With Survival From Out-of-Hospital Ventricular Fibrillation Cardiac Arrest
Background: Previous investigations in human cardiac arrest due to ventricular fibrillation (VF) have shown that analysis of the frequency-based waveform characteristic, amplitude spectral area (AMSA), can predict defibrillation, but has not previously been investigated for survival outcomes. We sought to investigate whether AMSA can be predictive of prehospital return of spontaneous circulation (ROSC), hospital admission and survival to hospital discharge.
Methods: Adult patients with witnessed out-of-hospital cardiac arrest (OHCA), of presumed cardiac etiology with an initial rhythm of VF from an Utstein-Style database (collected from 2 sites in Arizona) were included. AMSA was measured immediately prior to each shock, and then averaged for each individual subject (AMSA-ave). Associations between AMSA-ave and outcomes were assessed by logistic regression and receiver-operator characteristic curves.
Results: 89 subjects were analyzed (70 M, 19 F, mean age 62± 15 yrs), with a median of 2 shocks/subject (range 1-11). AMSA-ave was significantly associated with prehospital ROSC (p=0.003) with an area-under-the-curve (AUC)=0.70; an AMSA-ave threshold = 20.9 mV-Hz yielded a sensitivity of 95% to predict pre-hospital ROSC with a specificity of 43.4%. AMSA-ave was also associated with hospital admission (p<0.001), with an AUC=0.74; an AMSA-ave threshold=21 mV-Hz yielded a 95% sensitivity with specificity of 54%. AMSA-ave was also associated with survival to hospital discharge (p<0.001, AUC=0.75) and an AMSA-ave threshold=25.6 mV-Hz gave a 95% sensitivity with specificity of 53%.
Conclusion: We found that AMSA is highly associated with prehospital ROSC, survival to hospital admission and survival to hospital discharge in witnessed VF OHCA due. If future prospective studies validate these findings, AMSA computed during resuscitation may be useful to identify patients unlikely to survive and those for whom further resuscitation efforts would be futile.
- © 2013 by American Heart Association, Inc.