The EKG will always be performed its chest pain ! Some studies hold the view that EKG changes such as considerable Right Ventricular Strain St segment elevation in avr and T wave inversion in V1-V4 plus bedside Echo evidence of RV strain - is worthwhile .
I'm pretty sure that I heard Dr. Mason say that the hemoccult test detected iron. Thought it detected hemoglobin (human or animal) and peroxidases (from vegetables). Iron could cause a falsely melanotic appearance, of course.
The Hemoccult test detects heme (well, it's much more complicated than that but it's a good summary). Heme has iron in it. However, a patient on PO iron supplementation should not have a falsely positive occult blood test. Thank you for pointing that out. Lots of other things can cause false positive and false negative Hemoccult tests.
Dr. Herbert suggested dialyzing patients with renal insufficiency after contrast and I believe one of Dr. Mason's residents suggested this, albeit not directly. I just wanted to bring up that this is something that has been studied. Although contrast-induced nephropathy is hotly debated, the effect of dialysis after contrast administration has been demonstrated to be unhelpful following contrast administration.
Yes. If you vasodilate, the tagged dye may flow around a lesion, thus decreasing the sensitivity of the test. Not that getting a study should preclude giving a therapy.
Interesting. I know that nitro does increase oxygen delivery to the heart and decreases preload further decreasing stress to heart muscle but I wasn't able to find good information on wether nitro makes a difference in mortality with these patients in particular, especially when they first get to the ER if withholding nitro for a little bit would make a difference in their outcome. so I'm wondering if controlling their pain with something like fentanyl and getting the scan then giving them the nitro would be in their better interest. But whatever it's just a thought, thanks for the reply!
I'm not aware of a direct mortality benefit either, but we do know that it does increase blood flow to the myocardium. I used to be a prehospital provider and later an ED medic in a shop that risk stratified chest pains into 4 levels based on age, risk factors, EKG, history and exam. the low risk chest pains were sent for a nuclear study (https://www.ncbi.nlm.nih.gov/pubmed?term=9316527). Prehospital, we would withhold NTG from any low-risk chest pain patient without ischemic changes on EKG in order to preserve the study, so if this is something you're interested in, it's important to have the prehospital folks on board. What's more important is to know what your cardiologists like to use as a diagnostic study in these patients.
Patients with true UA/NSTEMI (which presumably either have a dynamic EKG or a positive trop), we can reasonably infer that these patients have coronary disease, and thus many cardiologists would elect to take them directly to cath (or next day) to get the best look at the vessels and then stent if desirable. I would agree with the VCU group that the best value of nuclear scans lies in identifying those low-risk chest pains that are at a higher risk for a negative outcome, in which case fentanyl is an appropriate alternative for pain control, but I think you're setting yourself up for trouble if you withhold a medication to get a study only to then give the medicine when they return. Either they're low-risk and you need the scan to evaluate their risk (in which case the value of NTG is probably low anyway) or you have a patient with active CP and a dynamic EKG who doesn't need the scan in the first place.
one additional chest pain mimic, pancreatitis. I have had a few patients with severe chest pain radiating to the back that after a negative chest work up the lipase came back very elevated.
To join the conversation, you need to subscribe.
Sign up today for full access to all episodes and to join the conversation.
Ian L. - March 8, 2017 6:04 PM
The EKG will always be performed its chest pain !
Some studies hold the view that EKG changes such as considerable Right Ventricular Strain St segment elevation in avr and T wave inversion in V1-V4 plus bedside Echo evidence of RV strain - is worthwhile .
Robert S. - April 11, 2017 2:04 PM
I'm pretty sure that I heard Dr. Mason say that the hemoccult test detected iron. Thought it detected hemoglobin (human or animal) and peroxidases (from vegetables). Iron could cause a falsely melanotic appearance, of course.
Jess Mason - April 11, 2017 7:18 PM
The Hemoccult test detects heme (well, it's much more complicated than that but it's a good summary). Heme has iron in it. However, a patient on PO iron supplementation should not have a falsely positive occult blood test. Thank you for pointing that out. Lots of other things can cause false positive and false negative Hemoccult tests.
David P. - April 13, 2017 6:40 PM
Dr. Herbert suggested dialyzing patients with renal insufficiency after contrast and I believe one of Dr. Mason's residents suggested this, albeit not directly. I just wanted to bring up that this is something that has been studied. Although contrast-induced nephropathy is hotly debated, the effect of dialysis after contrast administration has been demonstrated to be unhelpful following contrast administration.
Jesse K. - April 14, 2017 8:51 AM
Would giving nitro to an unstable angina/NSTEMI decrease the sensitivity of a nuclear scan?
Andrew M. - April 28, 2017 10:52 AM
Yes. If you vasodilate, the tagged dye may flow around a lesion, thus decreasing the sensitivity of the test. Not that getting a study should preclude giving a therapy.
Jesse K. - April 28, 2017 11:58 AM
Interesting. I know that nitro does increase oxygen delivery to the heart and decreases preload further decreasing stress to heart muscle but I wasn't able to find good information on wether nitro makes a difference in mortality with these patients in particular, especially when they first get to the ER if withholding nitro for a little bit would make a difference in their outcome. so I'm wondering if controlling their pain with something like fentanyl and getting the scan then giving them the nitro would be in their better interest. But whatever it's just a thought, thanks for the reply!
Andrew M. - April 28, 2017 2:11 PM
I'm not aware of a direct mortality benefit either, but we do know that it does increase blood flow to the myocardium. I used to be a prehospital provider and later an ED medic in a shop that risk stratified chest pains into 4 levels based on age, risk factors, EKG, history and exam. the low risk chest pains were sent for a nuclear study (https://www.ncbi.nlm.nih.gov/pubmed?term=9316527). Prehospital, we would withhold NTG from any low-risk chest pain patient without ischemic changes on EKG in order to preserve the study, so if this is something you're interested in, it's important to have the prehospital folks on board. What's more important is to know what your cardiologists like to use as a diagnostic study in these patients.
Patients with true UA/NSTEMI (which presumably either have a dynamic EKG or a positive trop), we can reasonably infer that these patients have coronary disease, and thus many cardiologists would elect to take them directly to cath (or next day) to get the best look at the vessels and then stent if desirable. I would agree with the VCU group that the best value of nuclear scans lies in identifying those low-risk chest pains that are at a higher risk for a negative outcome, in which case fentanyl is an appropriate alternative for pain control, but I think you're setting yourself up for trouble if you withhold a medication to get a study only to then give the medicine when they return. Either they're low-risk and you need the scan to evaluate their risk (in which case the value of NTG is probably low anyway) or you have a patient with active CP and a dynamic EKG who doesn't need the scan in the first place.
Douglas F. - May 11, 2017 12:04 PM
one additional chest pain mimic, pancreatitis. I have had a few patients with severe chest pain radiating to the back that after a negative chest work up the lipase came back very elevated.