So...... Is the whole "giving nitro to people having a right ventricular MI will tank their BP" thing a myth?
Or is it that people with right sided involvement will usually have soft pressures to begin with, and so don't meet the criteria for nitro anyways?
Relevant paper...
https://www.ncbi.nlm.nih.gov/pubmed/2502902 Full text here
Gurby the rest isn't directed at you, but more to the topic.
Most RV MI are hypotensive already... but not all... so we can't assume no RV involvement if normotensive
RV MI are typically preload dependent. Nitro will drop your preload. Will it drop it enough to tank the pressure of a normotensive RV involved patient?
Sometimes. So do they have RV involvement?
Many RV involved MI are going to have bradycardia... maybe extra n/v... but that is not sensitive/specific...
Bad RV MI may have appreciable JVD, but that is hardly sensitive/specific to RV involvement...
Basically we cannot form a reliable diagnosis or exclusion of RV involvement from vitals and physical findings, just suspicion.
We need a
good EKG which can tell us about inferior wall, which is sensitive to RV involved STEMI but maybe 40% specific.
But absent that, a patient who meets criteria for nitro is unlikely to have RV involvement. Unlikely is far from a rule out. So do you withhold the nitro for BLS? It's a gamble, isn't it! Is an EKG equipped unit right around the corner or we are 2 minutes out from the ED? No... well then we stack our odds with an IV before giving the nitro so we can fluid bolus to restore preload...
And if we have none of that, is the benefit for the patients who aren't preload dependent outweighed by the negative effects of tanking the few that are? I guess we still think yes, but I don't have that answer from the data. Hopefully someone more familiar with the data will come along.
Paging cardiology...