Detrended fluctuation analysis predicts successful defibrillation for out-of-hospital ventricular fibrillation cardiac arrest☆

Received 12 September 2009; received in revised form 2 November 2009; accepted 1 December 2009. published online 13 January 2010.

Abstract

Aims

Repeated failed shocks for ventricular fibrillation (VF) in out-of-hospital cardiac arrest (OOHCA) can worsen the outcome. It is very important to rapidly distinguish between early and late VF. We hypothesised that VF waveform analysis based on detrended fluctuation analysis (DFA) can help predict successful defibrillation.

Methods

Electrocardiogram (ECG) recordings of VF signals from automated external defibrillators (AEDs) were obtained for subjects with OOHCA in Taipei city. To examine the time effect on DFA, we also analysed VF signals in subjects who experienced sudden cardiac death during Holter study from PhysioNet, a publicly accessible database. Waveform parameters including root-mean-squared (RMS) amplitude, mean amplitude, amplitude spectrum analysis (AMSA), frequency analysis as well as fractal measurements including scaling exponent (SE) and DFA were calculated. A defibrillation was regarded as successful when VF was converted to an organised rhythm within 5s after each defibrillation.

Results

A total of 155 OOHCA subjects (37 successful and 118 unsuccessful defibrillations) with VF were included for analysis. Among the VF waveform parameters, only AMSA (7.61±3.30 vs. 6.30±3.13, P=0.028) and DFAα2 (0.38±0.24 vs. 0.49±0.24, P=0.013) showed significant difference between subjects with successful and unsuccessful defibrillation. The area under the curves (AUCs) for AMSA and DFAα2 was 0.63 (95% confidence interval (CI)=0.52–0.73) and 0.65 (95% CI=0.54–0.75), respectively. Among the waveform parameters, only DFAα2, SE and dominant frequency showed significant time effect.

Conclusions

The VF waveform analysis based on DFA could help predict first-shock defibrillation success in patients with OOHCA. The clinical utility of the approach deserves further investigation.

Keywords: Ventricular fibrillation, Defibrillation, Automated external defibrillator, Electrocardiography, Fractal

a Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan

b Research Center for Adaptive Data Analysis, National Central University, Taoyuan, Taiwan

c Department of Emergency Medicine, National Taiwan University Hospital, No. 7, Chun-Shan S. Road, Taipei, Taiwan

d Institute of Systems Biology and Bioinformatics, National Central University, Taoyuan, Taiwan

e Division of Sleep Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA

f Division of Gerontology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA

Corresponding author. Tel.: +886 2 23562831; fax: +886 2 23223150.

☆ A Spanish translated version of the abstract of this article appears as Appendix in the final online version at doi:10.1016/j.resuscitation.2009.12.003.

PII: S0300-9572(09)00626-1

doi:10.1016/j.resuscitation.2009.12.003

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