Nitroglycerin – SBP drop by one third. Is this a 1/3 drop directly after a dose of nitroglycerin or a cumulative drop after multiple doses/sprays? My understanding was that this 1/3 drop in SBP was being used to determine the pts sensitivity to nitroglycerin. If the pt had mild/moderate SBP drops after each dose it indicated that the pt tolerated nitro well and it was safe to give higher amounts and more doses. However, a large 1/3 drop immediately after a dose of nitro meant that the pt had a high sensitivity to nitro and further tx should be discontinued for pt safety and impending hypotension. Scenario: Ischemic chest pain (Non-STEMI) with an initial SBP of 180mmHg. 1/3 dictates a drop of 60mmHg. After 4 sprays of nitro (with mild SBP drops between each dose) the pts SBP is now 115mmHg. Is this pt exempt from further nitroglycerin because cumulatively their SBP dropped by more than 1/3 OR can I continue to treat because a large 1/3 drop was not seen following an isolated spray of nitro.

What is considered suspected cardiac ischemia? Is it just the presence of chest pain/ discomfort (heaviness or tightness). Are chest palpitations considered a chest discomfort as well?

In regards to the contraindication for NTG regarding SBP dropping by 1/3 or more, should we basing this off the very first BP obtained on that call, or a BP obtained right before NTG usage? Ie. ischemic chest pain 00:00 BP of 180/100 00:03 SBP of 150/90 00:04 NTG usage 00:09 BP 115/75. In this case a 65 (180-115) point drop would rule us out if 1st BP counted, but a 35 (150-115) point drop would not rule us if BP prior to NTG used. As pts can often be particularly stressed/anxious right when we walk in the door, it would make sense to me that the BP closest to actual administration would be most indicative of their true clinical state.

When we do a 12-lead and have inferior involvement, the directive states that we assume there is right sided ventricular MI and must confirm with V4R, and then states we should never give nitro for right sided ventricular STEMI. All of that is clear, but what I am wondering is that if the V4R is negative, does that clear the pt for Nitroglycerin use for the inferior STEMI, or does that simply help confirm the STEMI for the emergency department? Thanks.

Why do you only give 3 sprays of nitroglycerin to a STEMI positive patient?

If a dentist administers nitroglycerin to a patient who has no previous-prescribed use; does this constitute prescribed use at this point?