Date Published

January 31, 2012

Updated For

ALS PCS Version ALS PCS Version 5.2


Question: When treating a patient with suspected cardiac ischemia, should I acquire a 12-Lead ECG before giving nitro or ASA? If the patient is hypotensive, should I bolus at 20 ml/kg, or 10 ml/kg as per the cardiogenic shock directive? And how do I know if the patient has a right ventricular infarct? (Updated)


Paramedics should work as a team on scene. Ideally, obtaining incident history, applying the monitor and acquiring a 12-Lead ECG, assessing for indications and contra-indications for ASA and NTG should be performed in concert by a paramedic crew. The Medical Directors of SWORBHP do not wish to be so prescriptive as to dictate on scene which procedures if indicated are performed first.Do not delay one for the other. If appropriate, administer NTG or ASA or perform a 12-Lead when able. Short scene times are preferred. Although ECG changes are indeed dynamic, they are not so volatile most often to be changed dramatically within seconds to a few minutes.With that said, one strategy could be to give ASA first as it decreases mortality for MI, and nitro doesn't.

If the nitro makes them vomit then they may not keep ASA down. This strategy is only a suggestion based upon clinical experience and not a mandatory approach. The proper IV fluid bolus amount for a patient with suspected cardiac ischemia or STEMI should be 10ml/kg.A right ventricular MI is usually diagnosed by using right sided leads. Specifically, lead V4 is moved across to the right side chest to the same anatomic location. It is then called Lead V4R. If ST segment elevation is noted (classically in the setting of an inferior MI), then this is diagnostic of a Right Ventricular Infarct. It is true that a Right Ventricular Infarct would be not the ideal clinical situation to have NTG administered (that is why it is listed as a contra-indication if recognized on a 12-lead). With that said, classically Right Ventricular Infarcts are bradycardic and hypotensive.

This is exactly why the NTG directive is designed so cautiously. If a patient is bradycardic HR < 60 or hypotensive, or a patient drops their BP significantly with NTG administration (indicating pre-load sensitivity as seen in Right Ventricular Infarcts), then NTG is contra-indicated. These restrictions are designed specifically for the unrecognized Right Ventricular Infarct and herald back to a time before 12-lead ECG was widely deployed among paramedics.

*This question was updated on February 7th 2020



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