Question: I have a question in regards to right sided MI's. We had a patient that had slight elevation in his 12 lead inferior leads, but not enough to call for a STEMI. I once worked for a service that I could do a right sided 12 lead ECG. Are we allowed to perform right sided 12 leads here at SWORBHP if we do suspect an inferior MI?
An inferior STEMI with Right Ventricle (RV) involvement is a contraindication to nitroglycerin administration. Nitroglycerin increases the risk of hypotension and bradycardia, both of which are frequently found in patients with right ventricular infarction (RVI). The purpose of acquiring a pre-hospital 15 lead ECG is to look for RVI when an Inferior STEMI is present. There are changes to the language in the upcoming revision of the cardiac ischemia medical directive in ALS PCS that states Consider RVMI in all inferior STEMIs and perform 15-lead ECG to confirm. In these cases, a 15-lead ECG should be performed.
However, medical council does not support the use of 15-lead ECGs in the following circumstances:
- A patient, has an inferior STEMI, and a contraindication to the administration of nitroglycerin (e.g. hypotension, bradycardia, phosphodiesterase inhibitor use). Acquisition of a pre-hospital 15 lead ECG does not change your patient management because you will not administer nitroglycerin in the presence of an existing contraindication. Acquiring a 15 lead ECG potentially prolongs scene time and delays other care you need to perform.
- A patient with chest pain who has no evidence of an acute inferior STEMI on a 12-lead ECG. Isolated RVIs and or posterior MIs are very rare in this situation.
Bottom Line: The question to ask yourself is; how will this 15-lead ECG change my patient care management? If a contraindication for nitroglycerin use already exists, then acquisition of a 15-lead ECG to determine if another contraindication for administration of nitroglycerin is present, provides no benefit.