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Updated: Dec 7, 2025

A Model of Long-Term Ventricular Fibrillation in Isolated Rat Hearts
Published on: February 17, 2023
Frequency Variation of Ventricular Fibrillation May Help Predict Successful Defibrillation in a Rat Model of Cardiac
Wei-Ting Chen1, Min-Shan Tsai2, Shang-Ho Tsai3
1National Taiwan University Medical College and Hospital Department of Emergency Medicine Taipei Taiwan.
Background:
To evaluate whether the frequency variation of ventricular fibrillation (VF) helps to predict successful defibrillation in a rat model of cardiac arrest.
Methods:
VF was induced in rats followed by cardiopulmonary resuscitation and then defibrillation. The electrocardiographic signals of 30 rats with first-shock success were obtained from our previous animal experiments, and 300 rats without first-shock success were selected as control. The VF waveform immediately before the first defibrillation was analyzed.
Results:
Eighty-eight percentages of the frequency variations of an electrocardiogram (ECG) record falling in the range -9.5-9.5 Hz was selected with sensitivity of 0.8, specificity of 0.583, and area under curve (AUC) of 0.708. Compared with amplitude spectrum area (AMSA) (sensitivity = 0.767, specificity= 0.547, and AUC = 0.678), combining frequency variation and AMSA significantly increases the predictability with sensitivity of 0.933, specificity of 0.493, and AUC of 0.732 (p = 0.005).
Conclusions:
The frequency variation of VF may serve a useful parameter to predict defibrillation success.
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