LVH & LBBB in relation to Elevation in v4R
Question #6
Do LVH and LBBB also affect the ST segment in V4R, potentially causing right-sided ST elevation that can mimic right ventricular infarct?
I recently wanted to give nitro to a patient with the most classic cardiac ischemia symptoms you could ask for. He had LBBB that sounded potentially new onset, as well as 1mm of elevation in V4R - sign of RVI or mimic? I called the BHP to ask about whether I could/should give nitro in this case and, being put on the spot in the moment with a question about those right-sided leads almost nobody ever talks about, the doctor didn't know and couldn't look up an answer quickly (he ultimately said just make sure I have an IV first and then follow the nitro directive as usual - I did that, the patient's pressure stayed totally fine the whole time, and his chest pain improved somewhat).
I'm wondering if there even is an established answer to this question, given a little more time to come up with it than the BHP had when I patched.
Thank you!
Answer:
Yes LVH and LBBB can mimic ST elevation in v4R. When making the decision on whether or not to treat with nitro in this case, paramedics should assess for other signs of R sided MI such as lower heart rates, and lower blood pressures that are more typically found with R sided STEMI. For example, if the patient has a left bundle branch block and there is some ST elevation in v4R, their vitals are HR 62 and BP of 104/70, it may be prudent to withhold NTG for this patient and explain your decision making on your ePCR.
Medical Directive Category
STEMI
Published
23 January 2025
ALSPCS Version
5.3
Views
34
Please reference the MOST RECENT ALS PCS for updates and changes to these directives.