Worked an OT shift at my regularly assigned Engine on 2nd Watch... they were joking the other FF was Doctor Death because they're last shift they had a cardiac arrest, 1st Watch the day before had one... and then we had one ourselves...
(45 yo M at the swap meet who's cousin though he was just passed out, so no bystander CPR but <5 min downtime. Our AED can show a basic rhythm, showed asystole at first. EMS arrives, on their monitor, eventually a PEA rythm shows, hey we got pulses back, load into the ambulance, no pulse, resume CPR, a few rounds get ROSC again, you can see on the monitor they give Epi, good palpable pulse ~100bpm, lasts for maybe a min before bradying back down and re-arresting. Had like 5 or 6 rounds of Epi and an amp of Bi-Carb, got into the hospital with a pulse so hopefully they could do something to keep that going. Of course we never find out what outcomes...)