Skjeflo GW, et al. - Researchers examined the development of electrocardiogram (ECG) characteristics during advanced life support (ALS) from out-of-hospital cardiac arrest (OHCA) with initial pulseless electrical activity (PEA). Further, they explored the potential effects of adrenaline on these characteristics. In this study, patients who obtained return of spontaneous circulation (ROSC) displayed increased heart rate (47 beats per minute) and reduced QRS complex width (62 milliseconds) during ALS; while patients who received adrenaline but died increased their heart rate (22 beats per minute) without any concomitant decrease in QRS complex width. These findings suggested the prognostic value of ECG changes during ALS in cardiac arrest and the impact of adrenaline administration on these changes.