Association of Amplitude Spectral Area of the Ventricular Fibrillation Waveform With Survival of Out-of-Hospital Ventricular Fibrillation Cardiac Arrest

Abstract

AMSA is highly associated with pre-hospital ROSC, survival to hospital admission, and hospital discharge in witnessed VF OHCA. Future studies are needed to determine whether AMSA computed during resuscitation can identify patients for whom continuing current resuscitation efforts would likely be futile.

Real‐Time Ventricular Fibrillation Amplitude‐Spectral Area Analysis to Guide Timing of Shock Delivery Improves Defibrillation Efficacy During Cardiopulmonary Resuscitation in Swine

“…Analysis of the VF waveform in the frequency domain calculating its amplitude spectral area (AMSA) has been shown to inform on the likelihood that ROSC may occur after delivery of an electrical shock. 9,[14][15][16][17][18][19][20] AMSA reflects, in part, the energy state of the myocardium 21,22 and its readiness for successful defibrillation. 20,23,24 The highest value of AMSA is typically observed at the onset of VF.…”

Amplitude-spectral area and chest compression release velocity independently predict hospital discharge and good neurological outcome in ventricular fibrillation out-of-hospital cardiac arrest

“…In an investigation of 390 patients with VF cardiac arrest 12 , the amplitude-spectral area (AMSA) measured from the VF waveform indicated survival with a good neurological outcome. This was confirmed in a cohort of witnessed VF cardiac arrest in Arizona that showed AMSA was associated with hospital discharge and identified a threshold for AMSA below which survival was highly unlikely 13 . AMSA also predicted long term survival in a recently reported cohort in Italy 14 .…”

“…We previously examined a subset of this database, patients with witnessed arrest 13 , establishing AMSA-avg as a highly predictive factor for pre-hospital ROSC, hospital admission and discharge. In this investigation we have further examined the effect of witnessed status.…”

“…Return of spontaneous circulation (ROSC) was defined as a confirmed pulse for at least 5 min. A subset of this database of 89 subjects with witnessed arrest has been previously reported 13 , with 2 additional witnessed arrest subjects identified upon review and included in the current analysis. The primary endpoint was hospital discharge, and the secondary endpoint was a good neurological outcome, defined as a Cerebral Performance Category score of 1 (good cerebral performance) or 2 (moderate cerebral disability).…”

“…(EMS personnel were not instructed to deliberately hold compressions.) Amplitude-spectral area (AMSA), was then computed as previously described 13 , and in brief is the summed product of frequency, F i , and amplitude, A i , over a frequency interval of 4 to 48 Hz (resolved in frequency steps of 250/N Hz):…”