Evaluation of the reduction in time-to-defibrillation due to CPR artefact suppression in long duration out-of-hospital cardiac arrest

Diagnosis during cardiopulmonary resuscitation (CPR) is highly desirable because it has been reported to be determinant for a successful outcome from sudden cardiac arrest. This study evaluates the accuracy and the time-effect of applying CPR artefact suppression prior to rhythm classification with long out-of-hospital cardiac arrest episodes. A total of 191 episodes were considered corresponding to intervals between two consecutive defibrillation attempts. 127 maintained ventricular fibrillation as the underlying rhythm and 64 began in asystole but converted to a final ventricular fibrillation rhythm. The records comprised subintervals with and without chest compressions. A dual-channel adaptive filter is used to suppress the CPR artefact prior to applying the shock advice algorithm. The accuracy of the diagnosis during CPR is evaluated and the reduction in time-to-defibrillation and no-flow-time were computed.