The beneficial effect of basic life support on ventricular fibrillation mean frequency and coronary perfusion pressure

Background and objective: Chest compressions before initial defibrillation attempts have been shown to increase successful defibrillation. This animal study was designed to assess whether ventricular fibrillation mean frequen cy after 90 s of basic life support cardiopulmonary resuscitation (CPR) may be used as an indicator of coronary perfusion and mean arterial pressure d uring CPR. Methods and results: After 4 min of ventricular fibrillation car diac arrest in a porcine model. CPR was performed manually for 3 min. Mean ventricular fibrillation frequency and amplitude, together with coronary pe rfusion and mean arterial pressure were measured before initiation of chest compressions, and after 90 s and 3 min of basic life support CPR. Increase s in fibrillation mean frequency correlated with increases in coronary perf usion and mean arterial pressure after both 90 s (R = 0.77, P < 0.0001, n = 30; R = 0.75, P < 0.0001, n = 30, respectively) and 3 min (R = 0.61, P < 0 .001, n = 30; R = 0.78, P < 0.0001, n = 30, respectively) of basic life sup port CPR. Increases in fibrillation mean amplitude correlated with increase s in mean arterial pressure after both 90 s (R = 0.46, P < 0.01; n = 30) an d 3 min (R = 0.42, P < 0.05, n = 30) of CPR. Correlation between fibrillati on mean amplitude and coronary perfusion pressure was not significant both at 90 s and 3 min of CPR. Conclusions: In this porcine laboratory model, 90 s and 3 thin of CPR improved ventricular fibrillation mean frequency, whic h correlated positively with coronary perfusion pressure, and mean arterial pressure. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.