Acute Coronary Syndromes (old version, with sound) - CRASH! Medical Review Series

this talks going to be about the acute coronary syndromes which are unstable angina and STEMI and STEMI if you haven't seen the slides on angina yet you should probably look at that before you watch this so we talked about angina being chest pain with exertion and we talked about stable angina in the engine the slides and that's chest pain with exertion that's relieved with rest unstable angina is going to be chest pain with exertion that's not relieved with rust or it can also be classified as chest pain that's brand new or worse than previous episodes so in any engine of the pain is going to be substernal it's going to be described as crushing or heavy and it's the pain that lasts minutes to hours it's not going to be days to weeks so if the patient comes in and they say I have been having this chest pain for the last five or six days that's not aunt Jenna so sometimes you may have radiation to the upper arm shoulder that's not necessary though it's just one thing that is commonly seen in angina and angina is always a sign of coronary artery disease as far as we're concerned so this is again this diagram that shows sort of the classification the nomenclature of angina so angina is just the chest pain the substernal chest pain and then we have stable angina which is when it's relieved with Russ unstable angina what it's not relieved with rest and then unstable angina is broken into three different categories and so if you have an mi which would be the non STEMI and stem I then you this is characterized by the thing that these two have in common is that the cardiac enzymes will be elevated and that's simply because there's enough ischaemia to the heart cells that you're actually getting some necrosis and so you're spilling out cardiac enzymes the non mi unstable angina is just the Angie no that's not relieved with rest but you don't have positive cardiac enzymes the way you tell nan STEMI and stem me apart is based on EKG so any of the unstable angina diagnoses are classified as the acute coronary syndromes which is going to be the focus of this talk and any angina is due to coronary artery disease as far as we're concerned the only exception primarily is Prince metals angina which I gave a little belief a brief blurb to in the angina section okay so here's a vignette 62 year old man with a history of hypercholesterolemia presents to the ED complaining of substernal pain that he describes his crushing he says these episodes are brought on by going up the stairs or chasing after his dog and this episode has continued despite rest this is unstable angina so this is a patient that has unstable angina which when we have a patient that is older when I say older I mean over the age of 50 or 55 when they have symptoms that are consistent with unstable angina even if it's just regular old angina we need to get an EKG and the reason is the risk for angina are the risk for myocardial infarction when angina is present particularly unstable angina is so high and an EKG is so cheap and so easy that it is the most prudent next step and the reason is because EKG is going to tell you if you have st elevations which if you have st elevation you're going to move right on to treating stemming EKG won't tell you the difference between non mi unstable angina and non STEMI but it will help you weed out STEMI right away and that needs to be treated as soon as possible so your next step anytime you have a patient with unstable angina is to get an EKG you should also get cardiac enzymes but if you're asked on the USMLE what is the next step in the manage of this patient your answer is going to be EKG so you're also gonna have your cardiac enzymes meanwhile you should be giving this patient aspirin a beta blocker and nitrates usually nitroglycerine is fine and supplemental oxygen you should also give the patient morphine for pain relief now aspirin a beta blocker and well just aspirin in the beta blocker as far as we're concerned here those increase the survival rate they decrease mortality so you should know that the nitrates are good for the pain the supplemental oxygen is good for comfort and the morphine is good for pain those are all useful we give these yes to reduce pain but also to because when you have pain what happens your heart starts pumping more your heart rate goes up and the more the heart has to pump the more the more oxygen your heart is going to require so that's why we like to give these patients nitrates supplemental oxygen and morphine but it's also for the pain to the beta blocker reduces the amount of oxygen demand and that actually increases the survival rate so you should know that aspirin and the beta blocker are absolutely necessary those are at minimum necessary the nitrate supplemental oxygen and morphine are given but there they don't increase the survival the treatment is going to vary based on the result of the EKG and enzymes so your enzymes like I said will tell us if it's an mi or not but usually you're going to have the EKG first so you get an EKG and you have st elevation your diagnosis is stemming you don't even have to wait for the enzymes if you have st elevation of more than one millimeter in more than two leads then you have a diagnosis of ST elevation mi if you don't then you don't know if it's non stemming or just non mi unstable angina you'll have to wait for your enzymes to come back if the enzymes are positive but the EKG is equivocal then it's going to be non stemming you you're not necessarily going to see EKG changes in non stemming you could see EKG changes in non STEMI what you would see is signs of ischemia rather than science of infarction remember that signs of infarction are going to be st elevation so that's how we get STEMI signs of ischemia are going to be ST depression so if you see ST depression that's a hint towards non-stem but ST depression does not have to be there to have non STEMI what you would have is elevated enzymes in the presence of a normal or st depressed EKG so very important to be able to tell a non mi unstable angina and then on stemi stem okay so here's your cardiac enzymes the most important one the most specific one is going to be your ck-mb and so here's your ck-mb it's here in the in the dotted pink so the reason that this is useful is that it's going to be one of the first to to peak and so you'll have usually within four to twelve hours you're going to have an elevated ck-mb level so you'll have a pre shovel ck-mb level very quickly but you'll really start to notice that after four hours the nice thing about ck-mb is that within two days it's back down and normalized to an appreciable level to where if you have a new infarction you would see a rebound in your ck-mb so ck-mb is good for the initial diagnosis and it's good for when we have this patient who's had an mi and they're in the hospital and work we're checking them for reinfarction because we are concerned about that then the ck-mb will be something that will look for troponin is also good it helps us with our diagnosis but notice how it's it stays high for so long and so it's not going to help us for diagnosing reinfarction but it will be positive in patients who have an MI okay so I kind of gone over this but I really really really want to make this clear so what is the difference between STEMI and non STEMI so let's first talk talk about what they have in common so STEMI which is ST elevation mi and non STEMI which is non-st elevation mi they both cause cardiac enzyme elevations so they're both going to cause increases in your ck-mb and increases in your troponin so that they have in common they're both life-threatening emergencies that require treatment non STEMI can progress to STEMI it doesn't always it doesn't have to they're both dangerous but you have to keep in mind that both of these are life-threatening emergencies so they have to be treated with with emergent care and then both can be diagnosed as anterior lateral inferior and receptive posterior and so forth so we're going to look at how you can have different leads that are going to to have st elevation or ST depression and that's going to help us diagnose where exactly in the heart this occlusion or this ischaemia is what way artery and that's going to be helpful when we go into to to catheterize the patient so STEMI is a more severe occlusion which causes a transmural ischaemia so the occlusion is so severe that you have ischaemia from the outer layer of the heart all the way to the inner layer of the myocardium so this results in an ST elevation because what you actually have here is an ischemic lesion and so that results in an ST elevation in the relevant leads based on where it is if its anterior lateral so forth and in these patients we are going to give them if it's less than three hours since the onset we are going to give them fibrinolytic sit does increase the survival if given within three hours it increases survival by fifty percent so we do want to use fiber and fiber analytics on these patients because we would break the clot down there's already a clot in the patient so we want to break that down with non STEMI what we have is a blockage that causes a superficial ischemia of the myocardium so it's not full thickness and so that's the reason it doesn't cause the st elevation this may or may not result in st depression so if you see ST depression you should think non STEMI but ST depression itself all by itself doesn't mean non STEMI and the absence of ST depression doesn't mean you don't have non steffi so you can't just look at that what you look at to diagnose non-stem e is the absence of st elevation and a positive cardiac enzyme and in these patients we're going to give them heparin we're not going to give them fiber analytics and the reason is because they don't have an occlusion all they have is a blockage they don't have a complete occlusion so in these patients we don't use fiber analytics and the fibrinolytic i put here is tissue plasminogen activating factor that's the most common that we use okay so this is an example of non-stem this is an EKG and so look here look for the abnormalities so here you got one two three AVR AVL avf so here's your limb leads and here's your precordial leads where's the abnormality now you don't have to have this abnormality to be diagnosed with a non STEMI but it is present a lot of times and so let's say you've got this EKG and you have cardiac enzymes that are positive and you have this EKG you know that it's non STEMI because you don't have st elevation anywhere but what you do have is ST depression and the ST depression will help us diagnose where the non stemming is and the ST depression is right here and b4 b5 and kind of in b6 so the fact that you have ST depression and v4 and B 5s notice that the the the baseline is right here the depression is all the way down to here so since we have it more than two leads we have a non-stem eat and it's v4 and b5 so this is probably a lateral occlusion so this kind of is a schematic of what I just showed you here's another non STEMI so look for the ST depression here you kind of see it in to here but we're really going to be paying your attention primarily is 12 avf and then the precordial leads so here's the depression right here most prominent in v2 and v3 so this is more of an anterior infarct so I know I didn't talk about how you diagnose anterior lateral antro septal posterior we will bring that up in another section I can't reflect what the slides on here or not for that okay so here's STEMI so this is st elevation so remember when you have a patient coming in with unstable angina and you get that EKG right away because if you have st elevation you want to pick that up right away you don't want to be waiting for those cardiac enzymes to come back because if you have st elevation this patients in big trouble and if you have the st elevation if this patient is in big trouble you will see that st elevation and look at it's very obvious here st elevation right here this isn't this is your QRS complex here and this is your elevation so you have an elevation here elevation here elevation here and even a little bit on v4 so one two and three so this is an anterior ST elevation mi even possibly even an intro septum you can't really diagnose it on EKG alone but it gives you it gives you a clue so here's the st elevation this is kind of a schematic what it looks like P wave QRS complex and then because your baseline is or your your your baselines down here because your your st region is so high up it's going to make the T wave look like it's peaked so if you kind of go back here it looks like you got peaked t-waves this isn't hyperkalemia this is just your st elevation so you do have what looks like a peaked t-waves this is like your tea way right here but this is just an ST elevation so this isn't peaked t-waves this isn't hyperkalemia so this is just st elevation same here this isn't normal your T waves should only come up this high but what you have here is an elevated ST segment so this is st elevation it is not a peak ste wave so just something to keep in mind the difference between the two and your symptoms should point you immediately towards towards infarction and not towards hyperkalemia okay so where are the st elevations here they are right here so you got two and three and AVF so if you remember back to EKG two and three are your both your leads the limb leads that look downwards and AVF also looks downward so this is the lead that's placed on your leg so two three and AVF look downwards so when you have st elevation of 23 and ADF that is significant for a inferior mi so this is inferior wall mi so how do we manage so now we're going back to unstable angina and non steady so we've diagnosed the patient with non STEMI they have got positive cardiac enzymes and the EKG shows no signs of st elevation meaning no ST elevation of greater than one millimeter in more than two leads nor do they have a new left bundle branch block if a patient has left bundle branch block which I'll show you an EKG of and a little bit that also will classify that as STEMI so they have no ST elevation no new left bundle branch block but they do have positive cardiac enzymes well okay so first of all before we even get the cardiac enzymes when we have a patient with unstable angina like I said we're going to be giving the patient aspirin beta-blocker and heparin we're always going to do that then we're going to also give them supportive care so one hundred percent oxygen nitrates and morphine so this is what we always do for any patient with unstable angina that maybe just regular non mi unstable angina or n STEMI or STEMI when the patient is now diagnosed with non STEMI we're going to catheterize them so we have to catheterize them if it's non-stem me if it's unstable angina we don't necessarily have to so when we catheterize a patient for angiography that's in the case of non STEMI so if the cardiac enzymes come back positive but we're also going to catheterize the patient even if it's unstable angina if they have had a prior mi that's required intervention so pci or cabbage nem I would require intervention so if they if the patient has a history of any intervention so percutaneous coronary intervention or cabbage then or if they have CHF for chronic kidney disease or they develop hypotension or they've had prolonged pain those are all indications for angiography so know that these indications and know that always if you have diagnosed non stemming you're going to catheterize the patient when you whenever you catheterize the patient you're going to give them club pitta Grell which is an antiplatelet drug and a GP to be 3a inhibitor which if you remember it is eptifibatide and taro 5m so we always do that for patients that are getting catheterized clopidogrel and a GP to be 3a inhibitor and then if it's greater than 12 hours of the symptoms or PCI fails then cabbage is indicated and that would go out to the surgeon okay so here's that left bundle branch that I was talking about this is a left bundle branch block if you see this in a patient who's got elevated enzymes and they've got unstable angina symptoms or even possibly even if they just have unstable angina symptoms but I'm pretty sure the USMLE would give you the elevated enzymes that they threw this at you if they have elevated enzymes and a left bundle branch block you're going to treat this like STEMI not like non stomach even though you don't have st elevation here so the left bundle branch block what it is is in the QRS complex when you have ventricular conduction and the conduction is going through the left ventricle you have an infarct to there and that infarct interrupts the QRS complex and so what we get here is a little kind of a little notch and our QRS complex and you can see here this is more of a normal qrs complex that you see in lead one but in lead three and in lead avo and AVF you see this little notch on your on your QRS complex and that's a left bundle branch block and so this is going to be treated as stenting here's another one so here's one in a b3 a BF and two and you'll also see the when it's the left bundle branch block you'll also see it very proud well not necessarily very prominently but you'll see it in v1 v2 v3 and v4 when it's a right bundle branch I'm sorry you'll see in v3 v4 v5 and v6 when it's a right bundle branch block you would see it in v1 v2 v3 and v4 and that all has to do with where the leads are placed so remember your precordial leads v1 is on the right side of your sternum b2 is on the left side of your sternum and then v3 v4 v5 and v6 kind of wrap around your chest where your heart is v4 v5 v6 env3 RN left side and v1 v2 v3 and v4 are kind of considered on the right side so a left bundle branch block you'll see in two three avf and you'll see it in v3 through v6 a right bundle branch block which we don't see here would be seen in v1 through before and what I'm talking about seeing it's just that little notch okay so here's our algorithm on how to treat unstable angina and non STEMI so we've already kind of gone through this but this is kind of more of a graphic view so angina lasting 10 to 20 minutes or more that's not relieved by rest our first step is going to be an EKG and we're also going to want to get enzymes now I actually should have put this up here because you're not going to wait for your EKG you're you you're going to get your EKG first but at the same time when you're in the hospital at the same time you're going to be giving them aspirin beta blockers heparin and the supportive care but no note that you're doing all this at the same time but when they ask you on the USMLE what's your next step when the patient comes in with unstable angina your next step is EKG so EKG and enzymes if the EKG comes back in its st elevation it's stemming so we'll talk about that next if the EKG comes back and there is no ST elevation or no new left bundle branch block then it's considered unstable angina or non STEMI we don't know yet because we're waiting on the enzymes while we're doing all this like I said we're administering aspirin beta blockers and heparin all three of those increase your survival and then administering supportive care for the pink one hundred percent oxygen nitroglycerine and morphine once the enzymes come back if the enzymes are negative then if there's no other indications for angioplasty then we can discharge the patient or observe and remember what those other indications were for angioplasty those would be the patient has at a prior intervention if they've got congestive heart your chronic kidney disease hypotension or prolonged pain that's not responsive to nitrates in that case if their enzymes are negative it's not non STEMI or STEMI then we consider this just unstable angina that's been treated and we can discharge them or admit them for for observation but we don't need to do angioplasty on these patients that they have no indications and their enzymes are negative if their enzymes do though in fact come back positive or the patient has one of the other indications for angioplasty in the setting of unstable angina so hypotension CKD prior intervention or prolonged pain then we're going to treat this as non STEMI it is not Stephanie at the enzymes are positive and so what we then decide to do is at the time since the onset of the pain so you ask the patient one of the pain start if it was less than 24 hours ago you're going to send this patient in for angiography or for pci or well they'll probably do the angiography and the PCI at the same time but your next step is angiography and if they ask you what drugs to give before the end geography you're going to give them a GP to be 3a inhibitor and clopidogrel if it's been more than 12 hours or the PCI fails if the angioplasty fails then they're going to go in for cabbage all right so let's say that we've got this patient now and we've diagnosed them with stemi they have an EKG that's kinda they have unstable Angela they come in we hook up the EKG and they've got st elevation greater than one millimeter and more than great well this should say greater than or equal to two leads to leads or more or they have a new left bundle branch block that hasn't been diagnosed before we will treat this as STEMI so this would be STEMI and EKG changes are presumptive for the diagnosis so if you have the EKG changes do not wait for your enzymes you're going to treat this patient right away so we'll give them aspirin beta-blocker and TPA we're not going to give them heparin here why are we not going to give them heparin because in stemi the clot is complete it is generally a thrombus and so you have a complete blockage remember what heparin does it prevents clots from forming TPA breaks up clots so what we want to do in these patients is break up clots not prevent one from forming because we already have a clot we only give TPA if it's less than three hours from onset and generally these patients are going to come in right away because STEMI is significant pain so aspirin beta-blocker or ntpa of less than three hours from onset we're also going to give these patients the same supportive care oxygen nitrates and morphine these patients are going to be catheterized for angiography so we're going to administer clopidogrel and a GP to be 3a inhibitor and then from that point we look at we look at the catheterization after we've given them TPA if the recanalization is successful meaning if we broken up the clock and the EKG changes subside then we can admit this patient and we perform angioplasty percutaneous coronary intervention pci within 24 hours if the TPA is unsuccessful at breaking up the clot or the patient is more than three hours from on-site meaning we can't give them TPA or there's contraindications for TPA meaning that they've got a recent bleed they've had recent surgery then we give them we're going to perform rescue PCI immediately so we'll just go straight to an GI pot will go straight to angioplasty we won't wait the 24 hours or do it within the 24 hours if in any case the PCI fails if we run successful at stenting this patient and restoring circulation then we're going to proceed to cabbage and so this will be in the surgeon sense what you need to remember for the USMLE is that thrombolysis TPA is never the final treatment after you give them TPA you're either going to admit them and perform PCI within 24 hours if you've successfully reconized or we will perform a rescue PCI immediately if the recanalization is unsuccessful or we can't administer TPA either because it's too late or because there's contraindications so this is our STEMI algorithm so angina that is lasting for 10 to 20 minutes not really my rest as mentioned before we get EKG and enzymes and we would see an ST elevation here or a new left bundle branch block at this point we're treating STEMI so we're going to administer aspirin beta blockers and TPA if it's less than three hours and there's no contraindications will also give them the support of care as usual and catheterize them for their angiography so the USMLE is not going to ask you about supportive care I put that there because you might see it come up on the USMLE as what is the what is the best medical management for this patient or which of the following is going to increase survival just keep in mind with the support of care is and what the medical care is aspirin beta blockers TPA or heparin depending on whether it's STEMI or non STEMI respectively those are your medical treatment because that is going to increase survival the oxygen the nitrates the morphine is good you do it but it's not necessary because it's just supportive care it's not going to increase survival so these patients any patient with stemi we're going to catheterize them so we're going to give them their GP to be 3a inhibitors and clopidogrel if we have a successful recanalization we will admit them to the coronary care unit and do a PCI within 24 hours if it's not successful then we're going to do pci immediately if that PCI fails we'll move on to cabbage so remember the three-hour window for TPA so this I just want to cover when do we use pci and when do we use cabbage so remember the work up for when we use pci and cabbage remember how we do it in a stable patient so the patient with stable angina we're working them up we want to know if we have to revascularization with stable angina how do we do this well we get the angiography that tells us whether we do pci or cabbage it's a patient that has stable angina they've came back positive on their stress test and now we want to know if we do pci our cabbage we give them the angiogram and we find out that they have single vessel disease in that case we do pci very easy to put a stent in one vessel if they have multiple vessel disease or left main artery disease then they're going to need to be surgically operated and so in that case they're going to have to get to bypass surgery now when we have an mi patient we're going to do angiography right away we're going to try to do PCI as soon as we can because in stable angina what we usually have are our little occlusions in multiple different places in mi what we have is a thrombus in one place and so you have in unstable air in stable angina what you have our little clots in a lot of places but that aren't fully blocking the artery but in mi what you have is one totally occluded vessel that's causing a big problem in one specific area so that's why we get angiography always in mi patients and we're going to do PCI we're going to attempt PCI right away because we have a clot in one specific area and so we can do PCI whereas in the stable patient we want to look do we have because we're not in any emergency in the stable angina patient does this patient have just a significant blockage in one vessel in which case yes pci we can do or do they have significant blockages in multiple vessels in which case we're going to want to do a more thorough treatment of this patient so we do a coronary artery bypass but when the patient has mi we know that the problem is really only going to be in one area the big problem is only in one area so we're going to focus on that emergently and that's why we do PCI if the PCI fails then we do cabbage

Channel: Paul Bolin, M.D.

Views: 52,879

Rating: 4.9480519 out of 5

Keywords: usmle, step 2, step 3, cardiology, cardiology review, internal medicine, internal medicine review, resident review, medical student review, heart attack, acute coronary syndrome

Id: tqHSisLlo-Q

Length: 33min 1sec (1981 seconds)

Published: Mon Apr 15 2013