Stable vs Unstable Angina Nursing Mnemonics & NCLEX Review

Added: 2026-06-03

[00:00:00]Hey everyone, it's Nurse Sarah. In this video, I'm going to go over the differences between unstable versus stable angina. So, let's get started.

[00:00:07]Let's take a look at stable angina. This is also referred to as exertional angina. And to me, that's a little bit more of a fitting name because it tells me why this chest pain is occurring in the patient. And this type of angina is occurring because there is exertion. And we're not only talking about physical exertion, but we're talking about emotional exertion as well.

[00:00:28]So, whenever a patient is in an exertion type state, either physically or emotionally, their heart is requiring more oxygen-rich blood. So, that myocardium demands more oxygen. However, in cases of stable angina, those arteries cannot keep up with that demand. Now, why can't those arteries keep up with that demand? Well, in most cases of stable angina, it's due to a fatty plaque that has grown within that artery. So, whenever we have a nice little fatty plaque inside that artery, not only is it going to narrow the artery and limit the blood flow because that blood flow now has to go around that fatty plaque throughout rest of artery, but it's changed how our artery can work. So, now with that fatty plaque in there, that artery has become stiff.

[00:01:16]It's not as pliable or flexible as it used to be because normally, whenever you have exertion on your heart, your vessels can vasodilate or vasoconstrict to accommodate blood flow. However, when we throw this fatty plaque in there, they're more stiff and they can't dilate as needed whenever we have this exertion on the heart. So, we're limiting the blood flow that we can normally put through there. Now, this fatty plaque that is in this patient's artery is right now considered stable. It's not causing any problems. It hasn't ruptured causing a clot to form and blocking blood flow. But, over time, chances are this plaque could become unstable and lead to unstable angina, which can lead to a myocardial infarction. So, really, this may help you think of stable angina as being really that first step that happens early on before a myocardial infarction happens. Now, since this type of angina is exertional, it comes on whenever the patient has physical or emotional stress on them, there's some hallmark things that you want to remember about this type of angina. So, to help us sum up all of that information, help you remember this stuff for exams, remember these big takeaways. So, we're going to remember the four S's for stable angina. First S is see it coming. It's predictable. For instance, they know that if they walk up that flight of stairs or if they start to get stressed emotionally, chest pain is going to come on. Next S is short-lived. It's going to be 15 minutes or less. It's going to stop whenever they rest or they pop in some nitroglycerin. And these arteries are stiff. They are stenosed. They are limiting blood flow, and that's from this fatty plaque. Now, for a moment, let's talk about nitroglycerin, because that was one of our S. We know that with stable angina, nitroglycerin can relieve it. So, there's some things you want to educate your patient about, plus you want to be familiar with whenever you're working in the hospital. So, what in the world is nitroglycerin? Well, it is a vasodilator, meaning it opens up our vessels, which is definitely what we want when we have limited blood flow going to our heart. And this medication is part of the nitrate family. Now, how do you give nitroglycerin? Well, you can give it various ways. You know, you can start a drip of nitroglycerin. You can give it under the tongue and so forth.

[00:03:35]So, typically, whenever a patient is going home on this, they're not going to have a drip, of course. They're going to be taking either some tablets underneath their tongue, one tablet with each dose, or they're going to be using some type of spray. And what this is going to do is that within minutes after administering this, it is going to cause that vessel that is stiff and not wanting to cooperate to open up. So, that blood flow can go through that artery and they're going to get relief with their chest pain. Now, with this you want to make sure you educate the patient about how to take it and when to seek medical attention. So, typically with nitroglycerin, you're going to give one tablet underneath the tongue every 5 minutes as needed for three doses only.

[00:04:18]And during this time, the patient needs to be monitoring their chest pain. Is it being relieved? Is it going away? Now, if they're in the hospital setting, you want to have them on the cardiac monitor. You want to be looking at that ECG, especially paying attention to that ST segment. Are we having elevation or depression and those T waves? This could indicate ischemia and that our heart muscle is like actively dying. In addition, you want to make sure you're watching that blood pressure because nitroglycerin definitely decreases the blood pressure. And you want to make sure that systolic is staying within range and you don't want to throw more nitroglycerin on it. Now, if their chest pain isn't relieved after three doses, the patient wants to get immediate medical attention because chances are this has progressed to unstable angina and there's more going on. Or if you're in a hospital setting, you want to call a rapid response. Now, with the chest pain in stable angina, it's going to typically be felt below the sternum and it can radiate to the back, up through the arm or the jaw. And this really depends on the patient, male or female, because sometimes females are not going to have the typical chest pain. Instead, they could be extremely fatigued, have shortness of breath, and not really think that something is going on. So, you definitely want to educate patients on how to look for this. And another big thing is that if your patient is having chest pain with stable angina, this chest pain isn't going to gradually increase in intensity, like having that crescendo pattern that occurs in unstable angina. Now, with stable angina, there's no damage to the heart just yet. But, if this plaque does become unstable, we will get damage. So, one way we can look for damage in the heart is looking at troponin levels.

[00:06:03]With stable angina, those troponins typically are going to be negative because remember, troponin levels help us detect a protein in the blood that's released by muscle cells whenever they become damaged. In addition, when you look at the ECG of the patient's resting, not exerting themselves, it's typically going to look normal. However, on exertion, there can be some ECG changes such as ST depression, and those T waves can be inverted. This is telling us we got some ischemia. So, a big thing with this is we want to keep that fatty plaque stable. We don't want it to rupture. And there's some things that the patient can do to hopefully help prevent this from happening. One thing is following a low-fat, low-sodium diet.

[00:06:46]We want to decrease further plaques from developing and this plaque from growing even more. Plus, we want to lower sodium levels so we can keep that blood pressure within normal limits. And [clears throat] if the patient smokes, we want to educate them on the importance of quitting. And if they're diabetic, to manage their blood glucose cuz smoking and high glucose are very hard on your vessels. It makes them even more stiff, which is not what we want whenever we have coronary artery disease going on. In addition, we want the patient to have their cholesterol lowered, so they may be prescribed statins to help achieve that. Again, prevent those fatty plaques from growing or developing new ones. And we want to keep that blood pressure lowered, and we want to increase blood flow through the heart. So, there's a combination or various medications that can be used to do this. It's based on patients, like their kidney function, and what's going on with them. But, some medications that can be used include like beta blockers, calcium channel blockers, ACEs and ARBs.

[00:07:45]And I have a whole playlist on how these medications work and what they're used for that you can access up here. Plus, antiplatelet therapy can be used through aspirin. Now, why would we want to do that? Well, if this plaque does rupture, one of the first things happens is that platelets start to aggregate there. So, we can decrease the amount of that we can hopefully decrease um complete blockage from happening in the artery. So, they may be on aspirin as prevention. And depending on the case of this patient, what's going on, they may or may not be a candidate for a heart cath. And what a heart cath is in simple terms is that they go up through an artery, they enter into the heart's arteries, and they can go and open up that artery to allow blood flow to go through. So, we just talked about stable angina. We have, in most cases, a fatty plaque that is stable. But, over time, this fatty plaque can rupture, which leads us into the next type of angina, which is known as unstable angina. This type of angina is also called pre-infarction angina. So, this is a type of chest pain that occurs before a big event in the heart known as a myocardial infarction. Therefore, this is a very serious type of angina. And if your patient has it, they need treatment immediately because we need to investigate what's causing this and get them treatment so we can open up that artery and they don't progress to a myocardial infarction because potentially this is unsurvivable for their muscle cells and for the patient.

[00:09:15]So, with this type of angina, there is a decrease in oxygen supply to the heart.

[00:09:20]So, exertion isn't our problem. This type of angina can happen with minimal activity. So, it can happen at rest.

[00:09:28]Now, why exactly is it occurring? Well, we've already established that we've had a fatty plaque rupture. So, whenever a fatty plaque ruptures, it sets off a chain of events. So, we get some platelets going to that side. They think they're helping out, but instead they're actually making it worse because this little vessel is small. And they're going to get there, and then we're going to get the formation of a thrombus. And thrombus is a fancy word for clot. So, we're going to get a clot now hanging out in our artery. So, we went from a fatty plaque to a clot, which makes things a lot bigger. And this is going to act as a roadblock inside the artery.

[00:10:02]And this is going to partially block blood flow to the muscle. And over time, this occlusion is going to get worse.

[00:10:09]And as it gets worse, the patient is going to enter into the next phase, which is myocardial infarction. So, what are the key things you need to remember about unstable angina that makes it different from stable angina? So, let's remember the four uns for unstable angina. The first un is unexpected chest pain. It can happen at any time. They cannot see it coming. It's not predictable. It is unaltered. They cannot get relief with rest or nitroglycerin. It's unrelenting. It's going to last more than 15 minutes.

[00:10:40]They're going to have multiple episodes.

[00:10:42]It's going to increase in its intensity over time. Plus, you're going to start seeing shortness of breath, cold sweating, nausea, and vomiting. And they can have that gloom and doom where they feel like something really bad is about to happen. And again, these signs and symptoms can vary, especially for women where their signs and symptoms are as typical. And it's potentially going to be unsurvivable for their muscle cells and the patient's life if they don't get treatment. Now, in regards to troponin levels, they typically are negative.

[00:11:11]However, if the patient has a high sensitivity troponin done, it may be slightly elevated, but not too elevated where we're dealing with an MI. And the ECG can show some short-lived changes that could reflect ST segment depression or elevation or T wave inversion. But again, this is going to be very short-lived on that ECG. Now, this fatty plaque that has ruptured in unstable angina can get worse over time. So, the occlusion can get bigger and bigger where we have complete occlusion of that artery. So, that is where we start getting into non-STEMI versus STEMI territory. And these are both types of heart attacks. However, they differ in terms of severity and location of the blockage within that coronary artery.

[00:11:58]So, first let's talk about non- STEMI.

[00:12:00]This stands for non-ST segment elevation myocardial infarction. And with this type of MI, we have partial blockage of a coronary artery. So, whenever you look at the ECG, one of the defining things is that you're not going to see ST segment elevation. Hence, this is why it's called non-ST segment elevation. So, you're not going to have that. But, on the ECG, you could see ST depression or inverted T waves telling us we have definitely some ischemia to that heart muscle. Troponins can be elevated as well. So, whenever this happens, some treatments that could be used are starting them on a nitroglycerin drip. This will help increase blood flow to the heart cuz it causes vasodilation, which is what we majorly need in a condition like this.

[00:12:48]In addition, the patient can be started on a heparin drip, which is going to prevent further development of thrombus, hence clots. And the patient can be started on antiplatelet therapy through clopidogrel, which the brand name is Plavix. And this will help decrease platelet aggregation and prevent those platelets from sticking together so much. Now, depending on the patient's condition and if signs and symptoms have stabilized, a heart cath can be performed, which will help assess the coronary arteries, see where the blockage is, how bad is the blockage, and then treatment options can be discussed. The next is a STEMI, which stands for ST segment elevation myocardial infarction. And this is the worst of them all. So, non-STEMI is very, very serious, but a STEMI is extremely serious. The patient needs to be reperfused to the heart muscle immediately. So, with this, we have a complete blockage of a coronary artery.

[00:13:42]So, that heart muscle not getting perfused and it is going to die and it's going to be irreversible. So, whenever you look at the ECG, you're going to see ST segment elevation, as you can see in this example here. Whenever you see this, this is a very bad sign. Get your patient help immediately because it's telling us a huge area of this heart is not receiving blood flow. Whenever you look at the patient's troponin levels, they are going to be elevated telling us that some muscle cells have died and that is not a good thing. So, to help with this, what we can do is we can get them to the cath lab immediately. They can hopefully go in there if the patient's a candidate, put in a stent, open up blood flow to the heart and reperfuse that muscle. Or, if it's a really bad, severe case, they can go and get open heart surgery. Okay, so that wraps up this video. If you like to watch more videos, you can access the link in the description below.