 Welcome to Nursing School Explained. Today we'll go over coronary artery disease and how it leads to acute coronary syndrome and possibly myocardial infarction. So let's get started. First of all, acute coronary syndrome is caused by coronary artery disease or CAD, which is also known as arthral sclerosis. So I have drawn out here an artery and then we have that black plaque buildup here. So that plaque builds up mostly because of poor lifestyle choices and the most common cause is cholesterol. And then what happens is plaque kind of builds up here on the inside of the artery and platelets and blood flow goes through. But the platelets say, wait a minute, there's a plaque going on. Maybe there's something I need to repair. And so then they can aggregate and eventually if they clamp all together here, then we have a complete occlusion of that artery which can lead to a myocardial infarction because there's no perfusion distal to the part of that clogged artery. So when we think about coronary artery disease, there are basically three different types of angina, which is first of all, stable angina, which is basically the patient's complaining of chest pain with activity. So when there's increased oxygen demand because the patient is walking, they might get excited, they might get an argument. There's increased oxygen demand and so then their cardiac muscle is not able to perfuse that partially clogged artery and they're having chest pain. But when they rest or take medications specifically nitroglycerin, the pain goes away. So stable angina, pain with a predicted amount of activity relieved by a predicted amount or a predicted activity or intervention such as the medication nitroglycerin or risk. Now, the more severe case is the unstable angina which basically means that the patient has chest pain and rest. So now they're just resting, they're not exerting themselves, they're not physically active, but they are having chest pain, which means when we look back here at our artery that that artery is getting more and more clogged. So now there's no perfusion going through or maybe just a tiny bit and there is nothing that the patient needs more oxygen for because they're completely at rest and now they're having chest pain. Now that is a warning sign that something is going on and we need to intervene very quickly. And it says here, it's a precursor to MI, so myocardial infarction. And here we need to determine between the two types of myocardial infarction which is the STEMI, so ST elevation myocardial infarction or non-STEMI, so it doesn't have that ST elevation. And down here I've drawn out a picture of your normal cardiac cycle. And some of you might not have learned exactly what a dysrhythmia means or what an ST elevation means. So for the purposes of this video, we'll just very briefly cover that. So as you probably remember from your physiology class, the normal cardiac cycle has a P, Q, R, S, and a T wave and then this is just the normal EKG line that you would look at. And so we have the baseline, which is where the P starts and the T ends and they're both at the same level. Now when there's an ST elevation MI, that means that the ST element is elevated. And again, I've drawn that out here. So it again starts at this baseline and ends at the baseline. We'll have the P, Q, R, ST, but as you see this ST here is elevated and that usually means if you see that on an EKG, that's a warning sign that currently right now this patient's heart is not being profused. It can either be because of ischemia, so less oxygen flow or complete infarction. And at this point when we're running the EKG, we don't really exactly know and then we'll get into more diagnostic tests to determine what's going on with this patient. But ST elevation means that this segment of the EKG is elevated. Sometimes they also call it a fireman's hat, but because if you look at it, it could look like a fireman's hat. So that's another way to remember. Now the third possible angina or acute coronary syndrome is called Prince Meadows angina, also known as variant angina. And that basically is a little bit of a different kind of angina and that means that the spasm or that the patient's pain is caused by coronary artery spasm, which is a completely different cause than this plaque buildup that we have there, although it can still lead to complications, but typically the patient is treated with calcium channel blockers and that keeps the symptoms at bay. Of course, they're gonna need special investigation to make sure that nothing else is going on, but this is a different kind of angina from the stable and unstable. So now let's look at signs and symptoms the patients might be complaining of. Big one is always chest pain. Specifically, patients will complain of the subternal chest pain that feels like an elephant is sitting on my chest and then the pain can radiate. A lot of times an indication that there's something cardiac related as if the pain radiates to the left arm, to the jaw or all the way through to the upper back area. And men in specific are more prone to this type of chest pain where they say, I feel like an elephant sitting on my chest is really significant and it radiates into all these different areas. Another complication can be shortness of breath because clearly when there's something going on with the coronary artery that is being clogged, there's not enough perfusion going to the cardiac muscle, the body will try to compensate and then they will start to hyperventilate and try to pump more oxygen to that area of plaque and the patient will therefore be complaining of shortness of breath. Now patient also will maybe say that they're sweaty or you will observe that their skin is pale, cool and clammy and that means that currently because the cardiac muscle is suffering that all the blood flow gets shunted away to the most important organ which in this case is the heart. So the blood is shunted away from the skin, therefore the patient will present with cool, clammy skin because right now perfusion to the skin is not that important. The patient's system says, I'm gonna send every single blood cell that I have to this area of cardiac muscle that's not being perfused. Patient might complain of dizziness or the heart muscle is not pumping efficiently, there might not be enough blood flow, the patient might be dizzy. Also if the patient might be hypotensive, it can lead to dizziness. The patient might faint, so they might have a syncopal event. Again, if there's not enough perfusion, the heart muscle is not able to pump sufficiently, the patient might faint. And then they might also complain of epigastric discomfort and nausea vomiting. So the heart is in the chest cavity, the stomach sits right below and sometimes it's very hard to distinguish. Patient complaining of chest pain might have some epigastric or some stomach issue. And also the patient of epigastric discomfort might be experiencing a heart attack. So when you see epigastric discomfort, be aware of the close relationship to the cardiac muscle right here and think that maybe this is a myocardial infarction, be extra careful. And I wrote down here women because women present with atypical symptoms. Most of the time they will not say, I feel this elephant is sitting on my chest. They will not be complaining of this significant pain and they might not even look clammy and short as the short of breath. So some women present with chest, I'm a little queasy, I'm a little nauseous, I have this unusual pain in my stomach. When it's a woman, think myocardial infarction or acute coronary syndrome and be aware and do the appropriate steps to make sure that this is not what's going on. Now risk factors that lead to acute coronary syndrome as we already discussed over here, it's everything that leads to this plaque buildup. So mostly it's a poor lifestyle disease but we have to distinguish between modifiable and non-modifiable risk factors. So modifiable is anything that you can change, actively change. So hypertension can be managed. Hyperlipidemia can be managed. Diabetes for the most part can be managed. Smoking, you can stop smoking. Obesity, you can also work on weight loss, sedentary lifestyle, getting more physically active and then alcohol consumption. So all these modifiable risk factors are things that we can actively work on with the patient. Hopefully before this happens and then also in the recovery phase to make sure that their risk for having acute coronary syndrome or myocardial infarction is decreased. Now non-modifiable risk factors, there's something that you can't do anything about. So gender, male patients are at higher risk for myocardial infarction. Race, diabetics type one, it's an autoimmune disease so they can't really change that. Age plays a big role greater than 65 and heredity. So unfortunately it's related to genetics. There's not a whole lot we can do about that. So keep in mind modifiable versus non-modifiable risk factors. And then when we treat the patient who's complaining of chest pain, typically we think of this acronym, MONA. Now I wanna throw out a little caveat here because a lot of times, too, we think first I'm gonna give morphine, second oxygen, third the nitrates and fourth the aspirin. That's not necessarily the case. It depends on how the patient is presenting and typically you wanna start with oxygen, then give the nitrates, then give the morphine and then the aspirin. I'm just saying this is a very general rule. Don't quote me on that. If it's on a test question, make sure that you read the question very carefully and see what they're asking you and what your options of medications are that you're going to give. Now another caveat here is the oxygen. So studies recently have shown that there's no change in outcome for patients if they receive oxygen or not as long as the oxygen saturation is greater than 94%. So sometimes if you're working in the emergency department, the physician might not even order any oxygen for the patient if the patient's O2 sat is greater than 94%. And again, that's because of some most recent studies that have looked at how is the patient's overall outcome after they experiencing the myocardial infarction doesn't really matter whether or not we give up the oxygen because oxygen given in the long term can cause basal constriction which again will cause some more narrowing of the artery and then impair the blood flow. So for oxygen, just keep that in mind. And then in general, other medications that we can use are beta blockers and psychoagulants. So if there's a coagulation problem here with the platelets, then certainly the patient might need an anticoagulant to thin out the blood and preserve the blood flow or restore the blood flow. Thrombolytics, which are clot busters, ACE inhibitors, ARVs and statins. Now I understand that this is a very long list here, but for this video, I'm just gonna keep it brief to the list. Please look at the other video that goes into the detail, mechanism of action, side effects and nursing care really related to all these different medications for acute coronary syndrome. Now diagnostic tests, how do we know when the patient is having a STEMI or a non-STEMI or just stable angina? So diagnostic tests, we will definitely need to get a stat E12 lead EKG to see if the patient has an ST elevation. ST elevation means that there is currently impaired profusion to the cardiac muscle that needs to be resolved as soon as possible to prevent any kind of complications. Therefore, stat EKG. And then we wanna draw some cardiac enzymes. And there are three different cardiac enzymes that we typically look at. Proponent, CKMB and myoglobin. So these are all markers that we can measure in the bloodstream that will let us know what is going on with the patient's heart muscle. And CKMB and myoglobin are general markers of muscle breakdown where the troponin is cardiac specific. Therefore, I've underlined it. And all three of these cardiac muscle markers will be elevated at different intervals. They kind of work like the mechanism of action of a drug. Their onset peak and duration will depend on how soon that injury to that cardiac muscle has occurred. And troponin typically is elevated about four to six hours and then its peak is at about 10 to 24 hours. And then it might be elevated for 10 to 24 days after the cardiac event. Sorry, 10 to 14 days after the cardiac event. So now are we going to wait for 10 hours to see if that troponin is elevated or are we just going to treat the patient that has that ST elevation? Most certainly we're going to treat the patient. We're still gonna gather that data to kind of see a trend in their troponin. But if the patient had symptom onset an hour ago, you might not see the troponin being elevated right away. But if the patient has ST elevation, we need to get them treated and we'll go over that in a moment here. And for other diagnostic tests, certainly we wanna look at CBC, which includes a platelet count, which is very important to know because we know platelet aggregation causes a lot of trouble here. Also, we're going to give the patient an anti-platelet agent, which is the aspirin. So we're gonna wanna know that. And we're also gonna wanna know their basic blood count and hemoglobin and hematoclet. We also wanna look at their CMP for their kidney function, liver function, because we're anticipating this patient might need some intervention, some medications. So we wanna see how are they gonna be able to break down those medications we're gonna give them. We also might wanna look at their magnesium, which also is an important electrolyte for cardiac conduction. And also at their PT, INR, that coagulation studies because we know they might be getting anti-platelets and thrombolytics and or anticoagulants. We wanna know what their baseline PT INR is. Now for treatment, if the stable angina that we talked about before, the meds, the treatment will be medications. So nitroglycerin is a potent base of dilator that will just kind of help open up the artery and make that blood flow around that plaque easier. Now, most likely the patient will need some other workup to see what else is going on with the cardiac muscle. But for the acute coronary syndrome for stable angina, typically that's the treatment. Now, when it's unstable, so now the patient has this chest pain that is occurring at rest. And we basically need to assume that currently that cardiac muscle is not being profused, no profusion or low profusion can lead to ischemia, so low blood flow or infarction, and infarction is basically non-reversible. Myocardial infarction is when a part of the heart muscle dies and then that heart muscle is not going to be able to pump efficiently or at all. And then depending on the location where that death of that cardiac muscle occurred might depend on whatever complications the patient suffers and will go over complications in a moment. So the intervention for unstable angina is PCI, which means percutaneous coronary intervention, also known as angiogram. So basically the patient will go to the cardiac cath lab where the cardiothoracic surgeon or cardiologist will insert a camera into the patient's femoral or radial artery and thread that camera all the way up to the patient's heart to take a look inside the coronary arteries all the way around the heart to see how significantly stenosed these arteries are, what's the percentage of obstruction and what the best treatment will be to reopen these arteries. So I wrote here Plasminus stent. So they might put in a stent that kind of is a metal device that will just open an artery and hold it open. And the goal is to open the artery and to restore their perfusion. Now typically PCI, most emergency departments that are around the country, it's called door to balloon time, which means basically the time that the patient hits the door of the emergency department and then is taken to the cardiac cath lab is 90 minutes. So you can imagine there's a lot of stuff that's going on to get that patient there. And the reason is, if we don't intervene, the ischemia the patient is experiencing might lead to infarction that is irreversible. Now another treatment option is thrombolytics. Not every hospital in the country, depending on the geographical location has the capability of a cardiac cath lab. So if you're somewhere in a remote rural area, you're going to the emergency department that might not be available. So second option would be thrombolytics, which is also a treatment that we usually use for stroke patients and they're also called clot busters. So we could give the patient an IP dose of this clot busting medication that will circulate all over their body, hoping to dissolve the clot that's causing this issue here because of the coronary artery disease. Now thrombolytics are very, they can be kind of dangerous drugs and there's a lot of indications and contraindications. So look at the video about stroke where I discussed thrombolytics in a little bit more detail. And then thirdly, we have cabbage which is coronary artery bypass graft. And that basically means that the surgeon gets in and they're looking at the coronary arteries and they're finding three, four, five arteries that are majorly diseased, 90% closed. So there's not a lot of blood flow going on. They might just do what they can at the time of the PCI and open these arteries and then say, no, we actually have to go in and do open heart surgery and create a bypass for that patient. And the way I like to remember is it is think that there's a detour. So you're driving down the street and it's closed because of some construction. So you're gonna drive down the detour to get to your destination. And that's basically what it is. The construction site is the clogged artery and then we're gonna create a detour around that clogged artery. So what they'll do is they'll open the chest, they'll actually expose the heart and then they harvest the vein from another part of the body. A lot of times from the legs can be a mammary artery from the breast and they actually take out that artery and then they create that detour around that diseased heart or that clogged artery. And that of course is the most significant intervention where there's gonna be a lot of possible complications and a lot of post-op care. And then for our third type of angina, the Prince Menno angina. So nitroglycerin is the treatment if the patient is complaining of acute chest pain and the calcium genu blockers typically work very well for resolving this kind of coronary artery spasm that the patient is having. Now our nursing care, the goal is to increase coronary perfusion for the patient who's currently having an ST elevation MI or even if they're coming back to you to the telemetry floor after they've had one of these interventions. So most certainly we're gonna monitor vital signs because the heart pumps the blood around and we need to make sure and trend those vital signs. Now the patient is definitely going to need to be on telemetry for continuous cardiac monitoring because one of the complications is this rithmius. So when there's irritation in the cardiac muscle, the conduction system might be impaired and the patient is very prone to this rithmius. Therefore we need to keep the patient on telemetry to see what's going on with the heart rhythm. We're going to need to administer medications. Again, as long as that we discussed over here. Promote rest, which is very important because we don't want to increase the oxygen demand of the patient's body if it's already impaired. Certainly wanna decrease anxiety. Certainly the patient can be upset, afraid because right now they're experiencing a heart attack so the calmer we can keep them, again the less the oxygen demand of the heart will be and the better off they'll be for healing. We're gonna need to manage their pain. We talked about the significant chest pain that patients usually complain of so we need to manage that. And then facility transport to the cath lab if it's in the acute phase. And then certainly afterwards and during the entire patient hospital state we need to monitor for complications. And then once the patient is in more of the recovery phase then we can discuss lifestyle changes. So that will basically be focused on all these modifiable risk factors we discussed over here. So managing their hypertension, getting the cholesterol under control, getting them more active, managing their weight loss, getting them to stop smoking and stop drinking which all will benefit the heart in the long run. Now one last point here, complications. We already discussed that this rhythm is a myocardial infarction also can lead to heart failure because now that heart muscle is impaired and it cannot pump as efficiently. And then most definitely if we don't need to be effectively, efficiently and in a timely fashion the patient can die. So I hope this review has helped you to gain a better understanding of acute coronary syndrome and that plaque buildup that comes from the coronary artery disease. I will be discussing the different medications in more depth and different videos so please look for that. Thank you for watching Nursing School Explained.