Electrocardiographic waveform analysis for predicting the success of defibrillation

A new electrocardiographic predictor of the likelihood that an electrical s hock would restore a perfusing rhythm is described. The intent was to devel op a prognosticator that would be displayed during precordial compression. We anticipated that such a predictor would allow more selective timing of e lectrical shocks and reduce electrical injury to the myocardium caused by r epetitive shocks. In a porcine model of cardiac arrest because of ventricul ar fibrillation, electrocardiographic recordings of ventricular fibrillatio n wavelets were analyzed and transformed into an amplitude spectrum area (A MSA), An AMSA value of 21 mV.Hz predicted restoration of perfusing rhythm w ith a positive predictive value equivalent to that of coronary perfusion pr essure. More important, the negative predictive value that a shock would fa il to reestablish spontaneous circulation was 96%, AMSA, therefore, has the potential for guiding optimal timing of defibrillation.