'Probability of successful defibrillation' as a monitor during CPR in out-of-hospital cardiac arrested patients

The frequency spectrum of the ECG in ventricular fibrillation (VF) correlat es with myocardial perfusion and might predict defibrillation success defin ed as return of spontaneous circulation (ROSC). The predictive power increa ses when more spectral variables are combined, but the complex information can be difficult to handle during the intensity of CPR. We therefore develo ped a method for expressing this multidimensional information in a single r eproducible variable reflecting the probability of defibrillation success. This is based on the highest performing predictor for ROSC after 883 shocks given to 156 patients with VF. This was a combination of two decorrelated spectral features based on a principal component analysis of an original fe ature set with information on centroid frequency, peak power frequency, spe ctral flatness and energy. The function 'Probability of defibrillation succ ess' (P-ROSC(nu)) was developed by a 2-dimensional histogram technique. P-R OSC(nu) discriminated between shocks followed by ROSC and No-ROSC (P < 0.00 01). The present methodology indicates a possible way to develop a CPR moni tor. (C) 2001 Elsevier Science Ireland Ltd. Ail rights reserved.