SPECTRAL-ANALYSIS OF VENTRICULAR-FIBRILLATION AND CLOSED-CHEST CARDIOPULMONARY-RESUSCITATION

This study was designed to assess the interference by closed-chest car diopulmonary resuscitation (CPR) on the ventricular fibrillation (VF) ECG signal in a porcine model of cardiac arrest and to elucidate which variable of VF spectral analysis reflects best myocardial blood flow and resuscitation success during CPR. Fourteen domestic pigs were allo cated to receive either 0.4 U/kg vasopressin (n = 7) or 10 mi saline ( n = 7) after 4 min of VF and 3 min of CPR. Using radiolabeled microsph eres, myocardial blood flow was determined during CPR before, and 90 s and 5 min after, drug administration. Using spectral analysis of VF, the median frequency, dominant frequency, edge frequency and amplitude of VF were determined simultaneously and before the first defibrillat ion attempt. Using fillers in order to specify frequency ranges, stepw ise elimination of mechanical artifacts resulting from CPR revealed th at at a frequency bandpass of 4.3-35 Hz, median fibrillation frequency has a sensitivity, specificity, positive and negative predictive valu e of 100% to differentiate between resuscitated and non-resuscitated a nimals. The best correlation between myocardial blood flow and fibrill ation frequency was found at a median frequency range of 4.3-35 Hz. We conclude that spectral analysis of VF can provide reliable informatio n relating to successful resuscitation. In this model after eliminatio n of oscillations due to mechanical CPR, median fibrillation frequency best reflects the probability of resuscitation success. Copyright (C) 1996 Elsevier Science Ireland Ltd