Prediction of countershock success in patients using the autoregressive spectral estimation.

Objectives: Ventricular fibrillation (VF) is a life-threatening cardiac arrhythmia and within of minutes of its occurrence, optimal timing of countershock therapy is highly warranted to improve the chance of survival. This study was designed to investigate whether the autoregressive (AR) estimation technique was capable to reliably predict countershock success in VF cardiac arrest patients.

Methods: ECG data of 1077 countershocks applied to 197 cardiac arrest patients with out-of-hospital and in-hospital cardiac arrest between March 2002 and July 2004 were retrospectively analyzed.

Prediction of countershock success: a comparison of autoregressive and fast fourier transformed spectral estimators.

Objectives: Spectral analysis of the ventricular fibrillation (VF) ECG has been used for predicting countershock success, where the Fast Fourier Transformation (FFT) is the standard spectral estimator. Autoregressive (AR) spectral estimation should compute the spectrum with less computation time. This study compares the predictive power and computational performance of features obtained by the FFT and AR methods.

Comparison of mechanical characteristics of the human and porcine chest during cardiopulmonary resuscitation.

Background: Most studies investigating cardiopulmonary resuscitation (CPR) interventions or functionality of mechanical CPR devices have been performed using porcine models. The purpose of this study was to identify differences between mechanical characteristics of the human and porcine chest during CPR.

Material And Methods: CPR data of 90 cardiac arrest patients was compared to data of 14 porcine from two animal studies.

Frequency distribution effects of anchored mother rotors--a computer model study.

Recent findings indicate that major organized centers (mother rotors) can maintain ventricular fibrillation (VF). In computer models the mother rotors can be induced by local shortening of the action potential duration (APD) in the cardiac tissue. Because of the fact that these rotors tend to drift away towards regions with longer APD, an additional heterogeneity (e.

Improving countershock success prediction during cardiopulmonary resuscitation using ventricular fibrillation features from higher ECG frequency bands.

Background: Countershock outcome prediction using ventricular fibrillation (VF) feature analysis needs undisturbed electrocardiogram (ECG) signals and therefore requires interruption of cardiopulmonary resuscitation (CPR). Features that originate from higher frequency bands of the VF power spectrum may be less affected by CPR artefacts and as such reduce cumulative hands-off intervals.

Materials And Methods: From 192 patients with in-hospital and out-of-hospital cardiac arrest, four countershock outcome prediction features (peak-peak amplitude, mean slope, median slope, power spectrum analysis) were analysed in 550 short time ECG records, each including a CPR corrupted and a subsequent undisturbed sequence.