The JEMS Report: ROSC and Roll Cardiovascular perfusionist Brian Kress joins Mike Brown to dissect a high-stakes cardiac arrest case that underscores the critical moments following return of spontaneous circulation (ROSC). They walk through the fragile physiology of post-arrest patients and reveal how early, expert support in the field and hospital dramatically influences outcomes. From the importance of bystander CPR and prehospital interventions to advanced cardiac catheterization and mechanical circulatory support using the Impella device, Brian explains the science behind left ventricular end diastolic pressure (LV EDP) and how offloading the heart aids recovery. This conversation deep dives into the often-overlooked complexities of managing post-ROSC states, emphasizing the need for vigilant hemodynamic monitoring and judicious use of vasopressors. A must-listen for EMS, perfusionists and critical care providers seeking a nuanced understanding of cardiac arrest survival pathways beyond the initial resuscitation.