Before we get started, you have to understand which leads on the ECG correspond to which portion that's reading the heart. And what I mean by this is we group our leads into four different categories. So leads 2 3 AVF, leads 1 AVL, V5 and V6, leads V1 and V2 and leads V3 and V4. These correspond respectively to inferior leads, lateral leads, anterior leads and septal leads. Now often times V1, V2, V3 and V4 are all grouped into one category of four leads which we call anterior septal. And this is what that looks like. And the reason that this is important is because when you see different changes in these leads, you have to know which leads we're talking about. So if you see changes in 2, three or AVF, the pathology is inferiorly located. So those are the inferior leads shown here in green. Lateral is V5, V6, one and AVL shown in blue. V1 and V2 are anterior. V3 and V4 are septal. But they're oftentimes grouped into one big category where the four leads together are referred to as anterior septal. So they just com literally combine the words. So I want you to memorize that first. So pause the video and really get that down if you don't have it down already. But assuming that you do and you're comfortable with the way that these leads work, let's move on and talk about my pneumonic for remembering these leads. because again, if you're not there yet, you have to have a way to memorize this because this is very important when you're taking your board exam. So, I'm going to push that information to the left and draw my stick figure here. And when I was a medical student, it didn't really make a lot of sense to me that where the leads were in space corresponded to different parts of the heart. Now, if you're going to be a cardiologist, maybe you understand that geographic orientation, but I didn't go into cardiology. So, I needed a different way to memorize this. So, how I did this was with a few pneumonics. So the first one is 2 to three feet and feet are the most inferior portion of the body. So two to three for leads two and lead three and feet for AVF the F and feet for the F and AVF and two to three feet are always at the inferior portion of the body. So I remember that two to three feet are inferior. I also remember that one hand with five to six fingers is lateral. So one for lead one hand with five to six fingers for V5 and V6. And then the hand is the lateral most part of the body. So that reminds me that these are lateral leads and lateral for the L in AVL. You can use my pneumonics. You can do your fancy cardiology things that you try to do when you're a gunner and you impress people in medical school. But either way, as long as you know where the leads are, I'm fine with that. So this is a normal electroc cardiogram. And I think it's really worthwhile to stare at some normal ECGs before we talk about the abnormal ECGs because if you don't know what normal looks like, how the hell are you going to know what abnormal looks like? So, really take this in. Um, some medical students really get scared when they see V1, V2, V3, and V4 because they see that the ST segment might be elevated. But, um, I was lucky enough to do a rotation with a really, really great cardiologist when I was a medical student. And basically what he told me is that from V1 to V4, those ST segments are going to get a little bit bigger with each successive lead. So don't be scared. If it's if it's rising proportionally, then it's normal. If they're super off the page, then obviously it's going to be abnormal. And we'll get into all that as we go today. But the reason that I bring that up is because a lot of medical students look at V1, V2, V3, V4, and they're like, wait, is this a STEMI? Is this an ST uh segment elevated myioardial infarction? But it should go up from V1 to V4. So, this is normal. Stare at it. Get comfy with it. You're going to look at the ECG. You're going to find if it's sinus or not, and you're going to find out if there's any other abnormal findings like ST segment elevation, ST segment depression, Q waves for different types of eskeemia, etc. So, I don't want you to come into this lecture being like rate, rhythm, axis, the don't do that. That's not going to help you on USML and it's not going to help you on complex. Here is where you look for Pwaves. Now, the best leads to find Pwaves, according to the cardiologists that I worked with, is lead 2 and lead V1. They're just the most evident in those leads. And I've drawn in here with black arrows some Pwaves in lead 2 and lead V1. And they're kind of subtle, but they're definitely there, right? That you can clearly discern that there are Pwaves there. And where this gets tricky is medical students will look at an electroc cardiogram and be like, "Oh, I don't know. Is that a Pwave? Is it buried in the QRS? I don't know. Is that a Pwave? Is that little squiggly thing? Is that artifact? Everyone loves saying the word artifact. Is that artifact? No, it's a Pwave. Look in lead 2 and lead V1 and find Pwaves. If you find Pwaves, it's a sinus rhythm. So, here's our first one. The question is, what are we looking at? What kind of ECG is this? Okay, so pause the video if you want to think about it. But what you're seeing here is an ST segment elevated MI in the inferior leads. So what I'm showing you is the inferior leads, leads 2, three, and AVF. See those red arrows? They are pointing to ST segment elevation. And the reason that I put the blue arrow in is to show you that comparatively the ST segment of lead V3, which would be not in the inferior leads, is not elevated. So this is a STEMI localized to the inferior leads. Now, if you look at this ECG, I want you to theoretically ask yourself what would have happened if you went through this with that dumb methodical approach that they teach you in medical school. Well, rate uh duh duh duh duh duh rhythm. What do I see? Axis uh well, let's see. Well, it is upright and AVF is upright. So, the axis is normal. What does that get you? Where does that get you in this question? It gets you absolutely nowhere. Or you could just look at this and say, hm, two, three AVF have ST segment elevation. Let me compare the ST segments to the other segments. Well, none of the other ones are elevated. So, this is a STEMI. Is this sinus? Not that it really matters in this question, but we look at V1 and ICP waves. We look at two and ICP waves. So, it's sinus. So, it's a sinus rhythm, but there's an ST segment elevated MI. Done. Answer it. Check the box. Move on. That's that's what I'm saying here. Don't go through that methodical crap unless you're going into cardiology or you really want a mastery level understanding of ECGs. If you just want to dominate boards, do it this way. So, this is a STEMI. What do we see here? Pause the video if you need more time and in 3 seconds I'm going to tell you. This is another STEMI but this one is anterior septal. Right? So look at the red arrows. Those are ST segment elevations that corresponds to V2, V3, V4, V5 and V6. So V5 and V6 are lateral and V2, V3 and V4 are anterioreptal. So we combine them and we say this is an interosceptal lateral STEMI. And then look at the blue arrow, right? Look at AVL not really elevated. So we can localize this mostly to V2 through V6 which would be anterior lateral uh antioeptoal or antilateral. Now on a test they could simply ask you what type of STEMI is this and you would pick the answer that says anterior lateral or antioeptoateral or they could flip it on you and in the vignette describe the leads with the ST segment elevation or describe even the name. They could say something like interoseptoateral and then ask you which leads you would expect to find the ST segment elevation. And that goes back to my point. It's very important to be able to correlate leads to location. So those are STEMIS and STEMI are the highest yield ECGs that you could probably see on USMLA and complex because they're pretty easy to get. And to be fair guys on USMLE and Complex they have to give you very straightforward ECGs. They can't make it too challenging. If they did, it would be way beyond your level as a medical student and everybody would get the question wrong. And one of the themes of USML and complex is that the questions really can't be controversial. So that is an interoseptoateral STEMI. Let's move on to the next example. What are you seeing here? Now, this one's a little trickier. It's a little more subtle, but as soon as I point out the answer to you, I don't think you'll ever get this wrong again. So, pause the video if you really want to look and dissect this ECG. But in 3 seconds, I'm going to give you the answer. This is Wolf Parkinson white syndrome. And what I've highlighted here with the red arrows is what's called a delta wave. Now a delta wave is a slight upslanting of the beginning of the QRS complex. And this is classic of Wolf Parkinson White syndrome. Wolf Parkinson White syndrome has these delta waves, these slight upslling of the QRS. And if you really put on your bif focals and zoom in here, you can see that ups slanting portion of the QRS. Now in real life, this is a pretty rare disease, but on USML and complex, it's pretty high yield because that subtle finding, that upslanting of the QRS should tip you off that this is WPW syndrome. And then from there, they can go in a whole bunch of different directions by asking you things about pathophysiology, about the treatment for wolf Parkinson White syndrome. If you see the the answer procanomide, that's the answer. Um, but wolf parkinson white syndrome very very high yield. Be able to recognize this ups slanting. And again, I'm just really going to hone in on this. You don't have to dissect this ECG and go rate. What's the rate? Rhythm. What's the rhythm? Axis. What's the axis? You see the delta wave. The answer is WPW. So, what the hell is the point of doing the the methodical, dumb, unnecessary, waste of time method that you're seeing in all these other YouTube videos? Okay, guys, look for the pathological findings and answer the damn question. It's that simple. WPW has the delta wave that ups. Done. Moving on. What do you see here? This is a very, very high yield ECG. And it may not be obvious at first, but I want you to pause the video and look around and see if you can tell me what we are looking at on this ECG. wait dont react i will add other part tooo then make combined notes