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Updated: Feb 23, 2026
A Rat Model of Ventricular Fibrillation and Resuscitation by Conventional Closed-chest Technique
Published on: April 26, 2015
Ventricular fibrillation waveform measures combined with prior shock outcome predict defibrillation success during
Jason Coult1, Heemun Kwok2, Lawrence Sherman3
1Department of Bioengineering, University of Washington, Seattle, WA, USA; Center for Progress in Resuscitation, University of Washington, Seattle, WA, USA.
Aim:
Amplitude Spectrum Area (AMSA) and Median Slope (MS) are ventricular fibrillation (VF) waveform measures that predict defibrillation shock success. Cardiopulmonary resuscitation (CPR) obscures electrocardiograms and must be paused for analysis. Studies suggest waveform measures better predict subsequent shock success when combined with prior shock success. We determined whether this relationship applies during CPR.
Methods:
AMSA and MS were calculated from 5-second pre-shock segments with and without CPR, and compared to logistic models combining each measure with prior return of organized rhythm (ROR).
Results:
VF segments from 692 patients were analyzed during CPR before 1372 shocks and without CPR before 1283 shocks. Combining waveform measures with prior ROR increased areas under receiver operating characteristic curves for AMSA/MS with CPR (0.66/0.68 to 0.73/0.74, p<0.001) and without CPR (0.71/0.72 to 0.76/0.76, p<0.001).
Conclusions:
Prior ROR improves prediction of shock success during CPR, and may enable waveform measure calculation without chest compression pauses.
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