In this episode, Tyler interviews Tom Bouthillet and Dr. Stephen Smith on who exactly should get a right-sided ECG.
- Do not delay transport to PCI to grab a right-sided ECG.
- If you do decide to perform a right-sided ECG, it should not be for the decision on whether or not to give nitro.
- If time permits, it may be helpful and confirm your suspicions of RV involvement.
- Isolates RV infarcts are extremely rare.
In EMT school, I was taught how to assist a patient taking their own nitroglycerin if they developed chest pain. I had to make sure they weren't on any phosphodiesterase inhibitors, grab a blood pressure, and make sure they took the right dose. We would obtain a 12 lead, but I had no clue what I was looking at, and my decision to give nitro was not based on any specific ECG finding. Fast-forward to paramedic school, and I am taught to ALWAYS perform a 12 lead before giving nitroglycerin. Why? Wellll If they had an inferior wall MI, nitroglycerin was a hard stop. Every time the student would give nitro before obtaining a 12 lead in simulation, their patients would code...Every. Time. I thought this was weird because patients were prescribed nitroglycerin if they developed chest pain at home. They were certainly not performing a 12 lead on themselves prior to doing this. So what was the fear? The Fear EMS is full of cautionary tales
(as my buddy Brian Behn points out in this blog). The fear of administering nitroglycerin to a patient with an inferior wall MI is the possibility of plummeting the blood pressure if there is right ventricular (RV) involvement. Because the RV is preload dependent, dropping preload with nitroglycerin could cause hypotension. This is probably a good place to say that the LV is preload dependent too, but the LV preload is dependent on the RV preload. So if you wipe out the RV, the LV follows. I believe the fear of nitro is probably healthy, but not for JUST inferior wall MIs. The benefit of sublingual nitro has yet to be proven (as Dr. Smith points out in the interview) and on top of that, a study published in Prehospital Emergency Care in 2015 found that hypotension occurred post-NTG in 38/466 inferior STEMIs and 30/339 non-inferior STEMIs, 8.2% vs. 8.9%, p = 0.73. That means it makes literally no difference where the MI is.
