The physiology and potential of spectral amplitude area (AMSA) as a guide for resuscitation

Many studies aimed at understanding the electrophysiological mechanisms of ventricular fibrillation (VF) and defibrillation. Although many theories have been proposed about VF, we are still far from fully understanding it. Research has revealed significant insights provided by VF waveform, particularly through its amplitude of spectral area (AMSA). In fact, by potentially representing the energetic status of myocardial cells, AMSA has been shown in both animal and human studies to be a predictor of defibrillation success, return of spontaneous circulation (ROSC), early and long-term survival, and the presence of coronary artery disease underlying the cardiac arrest. The routine use of AMSA in the field could significantly improve resuscitation efforts and lead to a more advanced resuscitation technique by aiding in the selection of the appropriate timing and energy for defibrillation. The aim of this review is to explore what AMSA is and how real-time AMSA use could improve resuscitation directly from the field. If proven to improve patient outcomes, AMSA could significantly transform resuscitation practices, enabling more precise defibrillation strategies and enhanced patient survival.