Health Assessment, part 35: Heart Sounds

Hi. I'm Meris with Level Up RN, and in this video, I'm going to be talking to you about assessing the heart. I'm going to explain to you how to use your stethoscope, the different auscultation sites where you should listen, the expected sounds, and any extra sounds that you may hear. I'm going to be following along using our health assessment flashcards. These are available on our website, leveluprn.com, if you want to grab a set for yourself. Or if you prefer digital products, I would invite you to check out Flashables, which are the digital version of all of our flashcards. All right. Let's go ahead and get started.

So first up, I'm going to talk to you about how to assess the heart. We are going to be listening, auscultating, using our stethoscope. And there is an important thing for you to understand about a stethoscope. The stethoscope has two components where you listen, that part that you place on your patient, you can either use the diaphragm or the bell. Now, I'm going to talk to you first about the diaphragm. The diaphragm is usually the larger of the two options, and this one is used to listen to high-pitched sounds, and it requires that you place it against your patient with high pressure. So you need to forcefully hold that against your patient's skin. And that's going to assess-- that's going to let you auscultate high-pitched sounds. Then when you are ready to listen to low-pitched sounds, such as possibly a murmur or a bruit, you're going to turn the head of your stethoscope around and use what is called the bell. The bell of your stethoscope has a different shape to it, which allows you to listen and hear different sounds, and it is typically the smaller of the two options. In order to use the bell, you are going to listen using light pressure for those low-pitched sounds.

Now, I do want to give you our cool chicken mnemonic here, which is that you use heavy pressure, with an H, to listen for high-pitched sounds, with an H, by using the diaphragm of your stethoscope. There's an H in diaphragm. However, in order to listen to low-pitched sounds, with an L, you need to use light pressure, with an L, using the bell of your stethoscope. And the bell has two Ls in it. So that is our cool chicken hint to help you remember that. One word of caution that I do want to give you about your stethoscope is that you need to be familiar with how to use your particular stethoscope. Some stethoscopes have what is called a tunable diaphragm where you do not need to change the direction of the head. You simply need to regulate how much pressure you are applying when you listen. So I could place it in a spot, and I could push down hard with heavy pressure to listen for high-pitched sounds. And then I could let go and just rest it gently on the skin with light pressure to listen for low-pitched sounds. Every manufacturer and every stethoscope is going to be different, and you need to familiarize yourself with your specific equipment.

Okay. Moving on, I want to talk to you about the different auscultation sites where you will be listening to the heart sounds. You should be listening in five specific fields. These are called aortic, pulmonic, Erb's point, tricuspid, and mitral. And that might be a lot to remember. So luckily for you, we do have a mnemonic for this, which is APETM. That's the order in which you're going to auscultate, and that tells you the order in which to go down. And the mnemonic we have for you is, all people enjoy Time magazine. This is a very common mnemonic to help you remember those auscultory sites for the heart. But now let's talk about where you will hear them, where you should be placing your stethoscope. So the aortic valve is going to be on the second intercostal space along the right sternal border. So this is the only one that is going to be auscultated on the right side of the sternum for your patient. Then you're going to move over in that same intercostal space, second intercostal space. On the left sternal border, you will listen to the pulmonic valve. Then you will stay on that left sternal border and go down one intercostal space. In that third intercostal space, you will be able to hear Erb's point.

And why is Erb's Point important? I just want to throw this in as an aside. Erb's point is where you can hear all of the heart sounds, all of the different closures of the valves at an equal volume. So Erb's point, E for equal. Then you're going to move down, again, one more intercostal space to the fourth intercostal space along the left sternal border. And this is where you can auscultate the tricuspid valve. And remember, the tricuspid is that valve that separates the right side aorta from the ventricle. And lastly, I'm going to move and auscultate over the mitral valve, which is sometimes also referred to-- and if you recall in a video I did previously, I explained to you that this is sometimes called the point of maximal impulse. This is also kind of over the apex of your heart there, right at the bottom. And this is, of course, the fifth intercostal space. Now, we're not on the left sternal border anymore. We are now going to be along the left midclavicular line, that line that runs down the middle of the clavicle. So APETM, okay? That is where we are going to be assessing for those auscultory sites of heart sounds.

All right. Now let's talk about what I expect to hear and any sort of extra sounds that I might auscultate as well. So first off, let's talk about expected sounds. I expect that when I listen to an average person's heart, I will hear the S1 and S2 sounds. That is, respectively, the lub and the dub of lub dub, lub dub. Okay? So let's talk about what they are. The S1 sound is going to occur with the closure, the simultaneous, we hope, closure of the mitral and tricuspid valves. The valves that separate the atrium from the ventricles, when those valves shut, we get S1 or lub. Now, S2, or dub, comes about when the semi-lunar valves of the aortic and pulmonic valves close. So those valves that separate the ventricles, those close and give us S1. The valves that separate the aortic and pulmonic valves, those close and give us S2. Again, this is normal. This is expected. This is healthy. This is good. I like hearing these sounds.

So let's talk about some extra sounds. You may have heard of something called S3. And S3 is an extra sound that can occur kind of in the middle there of that cardiac cycle. And what this indicates is-- it can indicate fluid volume overload. So it can be associated with heart failure. It's caused by rapid filling during early diastole. So that sound is going to be that extra sound of a lot of volume rushing into the ventricles during that diastolic period. Now, S4, this is an extra heart sound caused by poor ventricular compliance. Compliance means how elastic are things. I want my ventricles to have good compliance where they snap back into place as soon as they're done contracting. So who has poor ventricular compliance? It's people who have had ventricular ischemia of some variety, such as patients who experienced a myocardial infarction. So if you have a patient with a prior history of a heart attack, an MI, you may auscultate that extra S4 sound.

Now, that's not the only extra sounds that we might have. We also can have murmurs. And murmurs are sounds that are caused by turbulent blood flow, which are caused by faulty or leaky valves. As that blood regurgitates through that incompetent valve, it will create this murmur sound, this whooshing sound. Sometimes these are completely benign and not harmless. Sometimes these are things we might grow out of as we age. But sometimes these can indicate to us some serious cardiac issues that need to be investigated. So a murmur is an extra sound that should always be investigated.

And lastly, I want to talk to you about a pericardial friction rub. Now, if you watched my video on the different types of adventitious breath sounds you might auscultate, you might remember me talking to you about a friction rub as being something associated when having two inflamed layers of a membrane rubbing back and forth upon one another. So when we listen to the lungs, and we call that a pleural friction rub, that's from the visceral and parietal pleura rubbing back and forth against one another. But when we hear that similar sound over the heart, this is called a pericardial friction rub because, again, it is the two layers of the pericardium rubbing back and forth against one another.

If you've never heard this, it is a very squeaky, rubbing sound. And when I have heard pericardial friction rubs, I think it sounds similar to a squeaky dishwasher or a squeaky washing machine where the belt in there needs more lubrication or is rubbing up against something, and it gives you that [inaudible]. That's a pericardial friction rub. And this is something that, again, it can be caused from things like maybe the patient recently had open heart surgery, or maybe I have something going on, like some variety of an infection or pericarditis that is causing that pericardial friction rub.

All right. So that is it for this video, but I'm so glad you stayed until the end because I've got to test your knowledge of key facts I provided in this video with some quiz questions. How should the nurse use the stethoscope to auscultate high-pitched sounds? By using heavy pressure with the diaphragm of the stethoscope. Where does the nurse auscultate for Erb's point? At the third intercostal space along the left sternal border. Which heart sound occurs due to the closure of the mitral and tricuspid valves? S1. An S4 heart sound may be auscultated in someone with what prior medical history? Myocardial infarction.

All right. That is it for this video. Thank you so much for watching. How many questions did you get right of those quiz questions? I want to hear. And if you have a great way of remembering something that I didn't mention in this video, I would love it if you would leave a comment. I love seeing those ways that you think of things and remember them, and I know that it's beneficial to other learners as well. All right. I'll see you in the next one. Thanks so much, and happy studying.