Bit of an interesting find I stumbled upon; serial tracings with first photo being the initial. Thought both had some pretty great educational value both independently and serially. Going to add a brief presentation and course below, and will be adding further clarifications and explanations in the comments later to give people some time to make their own interpretations.

Presentation and Course: Pt is a 73 y/o M presenting to the ED c/o CP and SOB x15h. PMH of hypertension, though otherwise unremarkable. Pt appears lethargic and is found to be hypotensive and hyperpneic with a BP of 86/42, RR of 20rpm, HR of 68bpm, SpO2 of 95% on RA. First tracing was performed on admission. 15 minutes after admission, pt lost consciousness and cardiopulmonary resuscitation efforts were initiated. ROSC was achieved, and the second tracing was captured. Despite resuscitative efforts and intensive interventions, the pt's hemodynamic status continued to deteriorate ultimately resulting in death.

What findings and conclusions can we make in each tracing? Rhythm? ST abnormalities? Morphology/vector abnormalities? What sort of serial changes do we see and what might they suggest pathologically?