Influence of Chest Compression on Amplitude Spectrum Area for the Prediction of the Return of Spontaneous Circulation in a Pediatric Swine Model

Amplitude Spectrum Area (AMSA) is a metric derived from the electrocardiogram (ECG) waveform during ventricular fibrillation (VF). Higher AMSA values have demonstrated strong predictive value for successful defibrillation and return of spontaneous circulation (ROSC) during cardiopulmonary resuscitation (CPR). However, there is no consensus on whether AMSA can be reliably estimated during chest compressions. We hypothesize that AMSA is affected by chest compression artifacts, but its predictive value for ROSC is not affected. We tested our hypothesis in a pediatric swine model of cardiac arrest (N=71). For each subject, AMSA was calculated for a pair of adjacent 4-second ECG VF segments prior to defibrillation, one during chest compressions and another during a pause. AMSA calculated during pause was higher than during compressions, both for ROSC (n=46; P<0.001) and No ROSC subjects (n=25; P<0.001). However, the area under the receiver operating characteristic curve for ROSC prediction did not differ between AMSA calculated during pauses and compressions (0.73; p=0.90). Thus, AMSA values were affected by compression artifacts, but ROSC prediction was not impacted. Our finding supports continuous monitoring of AMSA throughout CPR.