Abstract 18519: Is Amplitude Spectrum Area (AMSA) Affected by Various Depth and Rate of Chest Compressions
Introduction: Amplitude Spectrum Area (AMSA) is a proposed ECG-based indicator of ventricular activity during ventricular fibrillation (VF), which has demonstrated its value for prediction of effect of cardio-pulmonary resuscitation. In experimental pig studies, AMSA values >21 mV/Hz has been shown to be associated with higher probability of regaining return of spontaneous circulation (ROSC).
Hypothesis: Changes in depth and rate will change the AMSA values and thus affect defibrillation success in a pig model of cardiac arrest.
Methods: After VF induction, pigs were left untreated for 5 min after which chest compression started with three different chest compression patterns in a randomized fashion where the Group 5/120 received 5 cm compressions depth with a rate at 120/min, Group 4/120 received 4 cm compression depth at a rate of 120/min and Group 5/100 received a 5 cm compressions depth at a rate of 100/min. AMSA was calculated during 20 minutes of chest compressions prior to defibrillation.
Results: Comparing all animals regardless of ROSC or death levels >21 mV/Hz (Group 5/120: 22 (21-24)), Group 5/100 (22 (21-24))and Group 4/120 22 (21-24) (median (q1-q3)) could be found in all three chest compression methods up to the time period between 11-15 min of compression, after which a decline <21 mV/ Hz seen in all groups (Group 5/120: 20 (20-21)), Group 5/100: 19 (19-20)) and Group 4/120: 10 (10-11)). Independent of the chest compression parameters those that got ROSC had adequate AMSA values >21 mv/Hz in the period 5 min prior to defibrillation, in the Group 5/120 (n = 5, AMSA: 22 (22-22)), in the Group 5/100 (n= 5, AMSA: 21 (21-22)) and in the Group 4/120 (n= 4, AMSA: 24 (23-24)). AMSA values in the period 5 min prior to defibrillation in those that died was all lower than 21 mV/Hz (Group 5/120: 13 (13-15), Group 5/100: 9 (9-10) and Group 4/120: 4 (4-5)).
Conclusions: These result confirms the 21 mV/Hz AMSA predictive value to gain ROSC in pigs, however no differences in AMSA was seen in pigs that gained ROSC or death dependent on changes of depth or rate of chest compressions.
Author Disclosures: B. Madsen Hardig: None. J. Carlson: None. T. Sjöberg: None. S. Steen: None. P. Platonov: None.
- © 2016 by American Heart Association, Inc.