By Forrest Munden — 21-Year Firefighter Paramedic & NREMT Tutor
EMT Tutor Podcast · Paramedic (ALS) · 21:51
Show notes
This podcast is written by Forrest Munden and sponsored by Munden Interactive. I train paramedics and EMTs to pass the National Registry. A paramedic-level episode on STEMI and reciprocal changes for the National Registry exam. It covers what counts as real ST elevation under the Fifth Universal Definition of Myocardial Infarction and the 2025 AHA/ACC acute coronary syndromes guideline (J-point, two contiguous leads, 1 mm in most leads, and the V2–V3 numbers by age and sex), how Einthoven's triangle and the augmented and chest leads tell you which wall each lead is looking at, why reciprocal ST depression shows up in the leads pointing the opposite way, posterior and right-sided leads, STEMI equivalents, and prehospital care: the 12-lead within 10 minutes, PCI destination, aspirin, oxygen, and nitroglycerin cautions, with local protocol where the sources differ. For a written study guide, see EMS Notes, an EMT and paramedic study guide at emsnotes.com, also written by Forrest Munden. Education, not medical direction; follow your local protocols.
What this episode covers
- What counts as real ST elevation: the J-point, two contiguous leads, 1 mm in most leads (Fifth Universal Definition of MI, 2025 AHA/ACC ACS guideline)
- The V2–V3 numbers by age and sex, and why those leads get a higher bar
- How to measure: J-point against the TP/PR baseline, QRS onset in the acute setting
- Einthoven's triangle: how leads I, II, and III are built, and Einthoven's law
- The hexaxial system, augmented leads, and the chest leads in the horizontal plane
- SALI: which wall each lead is looking at, and what "contiguous" means
- Reciprocal changes: why the mirror shows up in leads pointing about 180 degrees away (III and aVL as mirror twins)
- When the mirror is missing, and why reciprocal depression helps separate STEMI from mimics
- Posterior MI ("up front, down back": V7–V9) and right-sided leads for inferior STEMI
- Prehospital care: 12-lead within 10 minutes, PCI destination and the 90-minute goal, aspirin, oxygen, and nitroglycerin cautions, with local protocol where the sources differ
Want it in writing? Study along with EMS Notes, an EMT and paramedic study guide at emsnotes.com, also written by Forrest Munden.
This is education, not medical direction. Follow your local protocols and your medical director.
More episodes: EMT Tutor Podcast
Learn more at https://emttutor.com
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