0:00 So now this is a topic that has been highly requested for a very long time. How many of you have gone through a class and haven't felt the most prepared to read 12 leads? Or maybe you feel like, hey, I know some basics, but I don't feel like very confident. You aren't alone. This one video is going to help you understand the rules of reading a 12 lead and it'll guide you on what you are looking for moving forward in your career. If you're new here, welcome. My name is Mike. I've been a lead paramedic instructor for about a decade. I've worked critical care as a flight medic. I've been a paramedic for a long time. And don't worry, I'm going
0:46 to get you to a point where you feel confident with yourself with reading 12 leads. Now stay till the end because I have a big announcement that I'm so excited about. We'll talk about it later. So talking about 12 leads, it states here ST segment should be at the isoctric line. If it is above, it's called elevation. This is known as myioardial inffection or a STEMI. And if it's below, it's called depression. Now go ahead and take a look at my cursor here. If you ever see a T-wave and there is a Pwave, look at the line that is in between those two beats. That line is called our isoelectric line. And the easiest thing to do would
1:32 be for me to take a straight edge. Sometimes I take out credit card, something of that sort, and I put it up against this line. Now, whenever I'm looking at an ECG, it's important to know, hey, where is my isoctric line? because that's going to help me determine am I looking at elevation or am I looking at depression. 12 leads can tell us many different things. What we're discussing right now is injury to the heart, physical damage to the heart tissue. So the 12 lead can also tell me about different axises or deviated axises of the heart. It can tell me which of the ventricles or atrium is enlarged. It can also show me different conduction problems. Now for most health care providers we're trying to determine
2:18 is there an injury or not. That is the main concern. Now there are some conduction stuff that I'm going to talk about a little bit later in this video. But the big takeaway from this is for you to be able to definitively say hey that's a STEMI or hey that's eskeeia which is a lack of oxygen. When it comes to axis deviation and it comes down to enlargement of different heart chambers, leave that to cardiologists, don't put so much emphasis, don't put so much stress on yourself. Let's learn this. All I'm doing with my eyes is I'm looking at this Jpoint. The Jpoint is that first change of direction right
3:04 after my QRS complex. So let's go and take a look at this one. It states here it's ST segment elevation. If I drew that invisible line just like we had before. Look where this J points located. It's definitely not at the isoelectric line as it should be here in normal. Right? So this is considered elevation. And if you know anything about elevation, elevation means injury. The heart is physically injured. So here's another tip for you. Whenever I'm looking for ST segment elevation, sometimes it's easiest to go backwards. Take a look at my cursor here. When I'm going backwards on my isoelectric line and I go up a T-wave, look how this T-wave goes back into my isoelectric
3:51 line. That means that there is no ST segment elevation. But let's go backwards here. I go backwards and I'm going up this T-wave and I never make it back down to my isoctric lines. There was a stop right here where there was a change in direction, right? And that change of direction just moves over into my J point. So if you remember what a QRS complex is, Q starts here. Q, this is my Rwave and this is my S-wave. My S-wave should always end at my isoctric line. It always should. But look how high this S-wave goes. It starts all the way up here. And my T-wave never makes it back down to the isoelectric line. So again, I just went backwards looking at
4:38 this T-wave and it never made it back. That is ST segment elevation. Take a look down here on my ST segment depression. I'm going backwards on this T-wave. It goes way below that isoelectric line and connects with this S-wave. This S-wave was supposed to make its way back up to my isoelectric line and it never did. That's a trick trick that you're never going to forget. Now, let's go ahead and take a look at this ST segment depression. Take a look at my cursor. We can see here that the J point is below the isoctric line. This change of direction occurs way down here, but it should be up here, right? So, that's an issue. That's telling me that this heart is lacking oxygen. Now, you might
5:26 say, "Well, Mike, if there's a lack of oxygen, doesn't that mean that it's going to be injured?" Well, yeah, eventually. Just because it has depression now doesn't mean it's not going to have elevation later. So, whenever I see ST segment depression, it is something that I'm concerned about. But I also want to know a little bit more about my patient. Does my patient show signs and symptoms of shock? For example, if my patient's septic and I see ST segment depression inside their 12 lead, well, yeah, I kind of suspect that because my patient has a lack of perfusion and a lack of perfusion is a problem for my heart because remember oxygen is carried in blood. So, this may be a diagnostic tool for yourself as a paramedic to say, "Hey, I should be taking this person to the hospital." But
6:12 it's not telling me that this person's physically having a heart attack right here, right now. But ST segment elevation, that's a bad sign. That's telling me that that patient's having a heart attack. Let's talk about some of those rules. Remember, STEMI stands for ST segment elevation myocardial infarction. The first thing, it must be seen in two or more contiguous leads. Now, sorry to go back and forth with explaining things, but this should help you make sense of it all. Whenever I look at a 12 lead, take a look at my cursor here, we get to see that we have 12 different views, right over here on the left hand side. This six comes from
6:58 your limb leads. Now, some of you I know are putting three leads. Some of you are putting four leads because one of those leads is a ground lead. But it provides six different views that we're able to look at. And the opposite side over on this side, this is called precordial. And our precordial side is our vector leads. And our vector leads are the six leads that we are placing down the patient's left side of their chest. And yes, up here on the top, that's where they're located. Please know all of that. That is mandatory that you understand this. Another interesting thing about knowing 12 lead ECGs and the national loves asking questions about this is which coronary artery is
7:45 supplying each of those leads on your ECG. So I would memorize that as well. Back to understanding what is contiguous. By the way, sorry if their color looks a little crazy here. I have a green screen that I'm using and it takes away the green color. So my apologies. It'll work. So let's go ahead and take a look at the limb lead side first. Limb lead side shows us that we have two lateral leads, one in AVL. By the way, A stands for augmented augmented vector right, augmented vector left, augmented vector foot. What I want you to pay attention to is the colors, right? So we got this color. Both of these are the same, which means they are contiguous.
8:31 So if I have ST segment elevation in lead one, I would also have to have ST segment elevation in lead AVL for it to matter. If there was no ST segment elevation here, but there was some in one, that means that it is nondiagnostic and I cannot call this a STEMI alert. Same here with 2, three and AVF. 2, three and AVF are inferior leads. I call this the boot. And you can see that I only need and now remember I only need two or more contiguous leads. So if all three of these are contiguous and I had ST segment elevation in two of them that makes it a STEMI. But if there's only ST segment elevation in one
9:16 nondiagnostic. Now the rules do change a little bit when we look at our precordial leads. So I do want you to think of like an imaginary line that separates both sides of your 12 lead. And let's go ahead and take a look at the precordial side. Now V1 and V2 are looking at the septum. So we call this septal. V1 and V2. And V3 and V4 are looking at the anterior portion of the heart. And V5 and V6 is considered lateral. Now the first misconception that I want you to know about 12 lead ECGs is V1 through V4 are all looking at the anterior part of the heart. All four of those are okay. I know that one is called septal and then anterior but just know that V1 through
10:02 V4 is all looking at the same part, same side of the heart. And you can even see down here at the bottom which coronary artery is supplying them. It's the same coronary artery, right? It's the same artery that runs down the middle of the heart. That's what we're looking at. Now, if I have ST segment elevation in lead V1, I would also have to have ST segment elevation in V2 for it to be considered contiguous, right? And if it's contiguous, that means that yeah, we're looking at a heart attack. If I see ST segment elevation in V1 and in V4, well, they're next to each other. It's not contiguous because it's not in line. Hear me out. If I took V2, which is septal, and I had ST segment
10:48 elevation in V2, and ST segment elevation in V3, that's contiguous. They're in line. Remember I mentioned that the precordial side is a little bit different than your limb lead side. Your limb lead side has to follow these colors, right? But our precordial side does not have to follow these colors because if they are in line with each other then they are considered contiguous. So that is a rule that I want you to always remember when looking at your precordial side of your 12 lead ECG. Now a lot of students ask well Mike what about V4 and V5? Sure it'll follow the same rule but I've never seen that or ever heard of that where it's just elevation here. Usually if you have ST segment elevation in V4 you're also going to have it in V3. And if you have
11:34 ST segment elevation in V5, you should also be seeing something in V6. Um, it's very rare that I would ever see just one of these leads having its own ST segment elevation. So, please remember that rule that there needs to be two or more contiguous leads for you to be able to diagnose. Now, let's go ahead and take a look at the next rules. If you've never heard of this, you should write this down. And I would be honest with you that most paramedics, at least that I know, uh, don't know all of these rules or they may have learned it in school, but they don't continue to use it out in the street. And that needs to change. Let's take a look. You must have greater than 2 mm or more in leads V2 and V3.
12:23 This is for men that are greater than 40 years of age. So if I take a look at that photo right there in the middle of your screen that states ST segment elevation, remember each one of those small boxes is 1 millimeter. So if we start at our isoctric line and we count 1 2 three boxes that's greater than 2 mm that would be considered ST segment elevation if it was found in lead V2 and V3. Understand that rule only applies for lead V2 and V3. Now the reason why these rules exist is you are going to come across 12 lead ECGs where there's going to be elevation found in lead V2 and V3 and it is nondiagnostic STEMI.
13:11 That person just has that ST segment elevation and it's completely normal for them to have that in their 12 lead. So, everyone's heart is different and not everyone's 12 lead is going to look identical. Pay attention to these rules. So, if they are greater than 40, it needs to be at least 2 mm or more and lead V2 and V3. Now, your next question might be, well, what if they're less than 40 years old? Can somebody still have a heart attack if they're young? Of course. There needs to be a rule for people who are less than 40 years of age. Take a look what this says. If it's greater than 2 and a half millimeters or more and lead V2 and V3, this is for men who are less than 40 years of age. If
13:57 somebody is in their 30s and they're having chest pain and you do a 12 lead and let's say it's 2 millimeters in V2 and V3, that is considered non-diagnostic because of their age. Now, if it's greater than 2 and a half little boxes, they're having a STEMI. Now, I know I just discussed a lot of stuff about men. What about women? Take a look. Greater than one and a half millimeters or more and leads V2 and V3. This is for women of any age. It doesn't matter the age of the woman. As long as it's greater than 1.5 mm in lead V2 and V3, they're having a STEMI. Now, this last rule here is my favorite because this makes my life so much easier because I know that's a lot to memorize.
14:42 But look at this. All other leads only require 1 millm of elevation to be considered injury. If I was looking at a 12 lead and I was looking at any of these other leads that are not V2 and V3, V4, V5, V6, 23 AVF, all I need is one small box. So that makes our life a lot easier. The only major rule that comes into different heights is only for V2 and V3. That's it. Everywhere else it's just 1 millimeter. Now that we understand that there needs to be two or more contiguous leads and the rules of what is ST segment elevation, let's take a look at what depression is. We all know that this is cardiac eskeeia, lack of blood flow. Only required to be a half.5
15:31 millime below the isoelectric line in two or more contiguous leads. Wow. only half of a small box in two or more contiguous leaves for it to be considered cardiac eskeeia. It's so small. So in this example, I'm showing you that this is considered an anterceptal STEMI. There are contiguous leads in between septal and the anterior leads. This could be V2 and V3. This could be V1 through V4. There's just a mix between those two and they are contiguous. Let's take a look. So now if we look back at the rules, we need to know what the patient's age is and we need to know are they male or female.
16:17 Let's say it was a male who was 68 years old. Well, they're greater than 40. That means that there only needs to be two or more millimeters of ST segment elevation and lead V2 and V3 for this to be considered injury. And we can look at this. I know it's very small. It's hard to read the little boxes, but that's pretty significant ST segment elevation. And this is even higher, right? So, this person's definitely having a STEMI. We can even see that we have ST segment elevation here in lead V1. And then I also have maybe very minor but a lot harder to see there, but there is some ST segment elevation. Remember in lead V4 there only needs to be one millimeter or more ST segment elevation. So this is
17:03 considered again antospyl. It's hard to say that this is considered a rule, but this is something that we as healthcare providers can get very good at catching when there is something that we call an impostor. So there's four different impostors that you need to know that exists. One is a conduction problem. We call this left bundle branch block. Then we have a enlarged left ventricle. We call this left ventricular hypertrophy also known as LVH. Then we have two interesting ones. They're called early repolarization and paricarditis. Typically how we can determine if these
17:49 are our impostors that we're looking at on our 12 L ECG is dependent on concave versus convex. Let's take a look at what this says. Concave is often known as a STEMI impostor. This is seen in early repole or paricarditis. This states convex. This is confirmed cardiac injury or a STEMI. So, take a look at these photos. I always think concave reminds me of like a halfpipe. If you've ever seen skateboarding or anything of that sort, like a ramp, that's more of a concaved appearance. But when you see this convex, that immediate change in direction in that Jpoint, that's a sign that your patient's having a STEMI. So, what I want you to do is I want you to
18:36 memorize that, hey, concave appearances can be signs of an impostor because I'm going to be showing you later on in this video, paricarditis, and early repolarization. I want you to be able to tell those concaved appearances from the convex appearances. Let's keep moving. Next, we're taking a look at a term called pathological Q waves. And this one is a little bit confusing to students. These are found when there is myocardial infarction. Infarction means tissue death. This is seen with prominent Q waves that has a greater than. 04 second duration. Remember, duration is what we're looking at from left to right on our ECG. or at least
19:22 1/4 the height of the QRS complex. So, we know these Q waves are not only going to be wide, but they're also going to be deep. Seeing this on an EKG confirms that the patient has previous heart issues, which means that this person could have had a heart attack in the past and that tissue is actually infarcted. That tissue has died. Take a look at how big this Qwave is compared to any other Q waves you've ever seen. This is considered a pathological Qwave. That J point is not telling me that this patient having any elevation. So right now I don't see any injury or I don't see any eskeeia that's occurring inside the heart. But seeing that that Q
20:08 wave is so large is telling me that this person had a previous heart condition in the past. Now the next rules that you need to understand deal with reciprocal change. It states here that some leads have reciprocal changes. These changes are opposite of each other. For example, if there's ST elevation in lead one and AVL, then the reciprocal change would be depression in leads 2 3 and AVF. Reciprocal changes are important to understand because it's a confirmation that the patient is suffering from an MI. Please understand this about reciprocal change. Not all leads on your 12 lead have a reciprocal change. For
20:53 example, V1 and V2, right? My septal leads, there's no reciprocal change. So, if I have ST segment elevation in those two contiguous leads, it's a STEMI. But there are some leads that do have a reciprocal change. Let's look down this list. We can see here that the anterior leads V3 and V4 do not have reciprocal change. If I said antosceptal V1 through V4, there are no reciprocal change. So all I need is ST segment changes in those leads for me to call it a STEMI. But what if it's in a lateral leads? What if I have ST segment elevation in V5 and V6? Well, 23 and AVF are considered reciprocal changes. So,
21:42 by definition, if I have ST segment elevation in V5 and V6, I should have ST segment depression in leaves 2, three, and AVF. Somewhere in those leads, I should be able to see a reciprocal change. Now, you might say, well, Mike, hold on. What if I don't see reciprocal change? What if I see ST segment elevation in my lateral leads, but I don't see ST segment depression in 23 and AVF or my inferior leads? Well, I would tell you I would still call it I would still say, yeah, I'm going to call this a STEMI and allow the hospital to make the decisions. From my experience from taking a lot of STEMI patients to the hospital, certain ER doctors would
22:27 never call a STEMI alert unless there was reciprocal change. Now, how do they confirm that that patient's having a STEMI? They need to draw labs. So, they're going to do blood work on that patient and they're looking for cardiac biomarkers. They're looking to see that the patient's troponin, which is a protein that if elevated confirms that that patient's having a heart attack or an MI. So, out of personal experience, I've taken patients with obvious ST segment elevation in two or more contiguous leads to the hospital. They said, "Hey, there's no reciprocal change. We're not calling it. Let's go ahead and get blood work instead, and we'll make a decision." Hey, that's okay with me. I took them to an appropriate facility with a Kath lab. They get to make those decisions. I just have to do
23:12 what's best by the patient. Let's keep looking at these reciprocal changes. Antrolateral saying that it is anterior and lateral. Okay, V3, V4, V5, and V6 obviously 23 and AVF because lateral is still included, right? If I look at the inferior leads, inferior 23 and AVF one and AVL is the reciprocal change. So, this one's really common that I see in exams. And when I see a ST segment elevation in 23 and AVF, my eyes will automatically go to one in AVL, I'm always looking for ST segment depression and leads one in AVL for me to confirm that yeah, I'm looking at an inferior wall STEMI. Now, this last one is a little bit more advanced. I don't see a
23:59 lot of EMS jumping on this yet, even though we should be. uh posterior wall, the back of the heart is a definite possibility that there could be a heart attack occurring there. A posterior wall is considered V7, V8, and V9. Now, you might be saying, Mike, hold on time. We don't have that many leads and I know that what a posterior wall STEMI is is you take lead V4, V5, and V6 off of the patient and you place it on the patient's back. I know that might sound foreign to a lot of you. We call this a 15 lead ECG. And what we're trying to look at is if
24:45 we note any ST segment elevation by placing leads on the patient's back. What might make me say, hey, let's go in and read the 12 lead on the patient's back. Well, take a look at the reciprocal change. If I have ST segment depression in lead V1 and V2, that's a sign that my patient might have ST segment elevation in the posterior leads. So that is the criteria to say hey we need to perform a 15 lean ECG is when we see ST segment depression and our septal leads. So again a little bit more advanced but this is how we do catch a posterior wall STEMI. So now that we've looked at the rules how do you feel?
25:32 Hopefully a little bit confident. I hope you made some good notes because now we're going to be diagnosing and looking at 12 leads together. Starting off with an anterose septal STEMI. We've already looked at one and this one might look pretty similar to what you saw before. This states STEMI found in leads V1 through V4. Now, please don't forget that all I need is two or more contiguous leads. I know it says V1 through V4, but what if it was V2, V3, and V4? That's fine. It's still contiguous. That's still an antcepteptal stem. In the following example, look at ST segments V1 through V3. The treatment aspirin, nitro, oxygen only if they're hypoxic and analesics. Let's take a look
26:20 at this 12 lead. Now, I think we can all agree here that we have some very obvious ST segment elevation. It's really occurring in lead V1 and V2. V3 is very suspect to me because it's kind of hard to see in this photo. Where is that change in direction? If it's greater than two or more boxes, if it's a male that is greater than 40 years of age, then yes, that is a STEMI. But I could definitively tell you that V1 and V2 are elevated. So, we have a STEMI just based off of that. But if V3 is also involved, then that is an antiroceptal STEMI. If it was just V1 and V2, it'd be
27:05 considered a septal STEMI. So, I know this video is about reading 12 leads, and I'm not going to get too crazy into treatment, but I will continue to tell you the treatment for each one. If you have any specific questions regarding the treatment, go ahead and ask me in the comments. Next, we're taking a look at an inferior wall STEMI. Look at lead 2, three, and AVF. Then look at any reciprocal changes in one and AVL. So, let's do that first before we talk about the treatment. So, taking a look at this 12 lead ECG, I can see two has massive ST segment elevation. Look at where that J point is, right? This person's having an insane STEMI. three, even more AVF,
27:53 even more. Remember, all I'm looking for is two or more contiguous. This has it on all three on our inferior leads. Immediately, my eyes are going to want an in AVL. So, when I look at one, I don't see any ST segment depression in one. But look at AVL. We definitely have ST segment depression. That right there, that is my confirmation that I'm looking at a STEMI. Just looking at the other side of this 12 lead, there's some other interesting things that are being seen in this 12 lead. Uh I have massive depression in lead V1 and V2. I have ST segment elevation in V5 and V6. Uh so I have a lot of other issues going on in the heart. This person's having a bad
28:40 day for sure. So if you know anything about diagnosing a inferior wall stemi, you might be saying we need to look at the right side of the heart and you are right. If you've ever heard of a lead V4R, what we do is we take lead V4, we take it off the patient and we place it on the other side of their chest. When we place it on the other side of their chest, we rerun the 12 lead. And then all we do is look at lead V4 to see if there's any changes to lead V4. If we see ST segment elevation in lead V4R, the right side of the chest, that's telling me that this person has rightsided injury to their heart. Now, which coronary artery is supplying the 2, three, and AVF? If you said the RCA
29:28 or the right coronary artery, you're right. And patients that have right coronary artery occlusion with a positive V4R, they're suffering from rightsided heart damage. Now, what do we know about the right side of the heart? Well, the right side of the heart is where we get deoxxygenated blood from the inferior and superior vennea. Well, if that's where blood is coming from, that's creating our preload, those patients are suffering from a lack of preload because the right side of their heart is damaged. This makes that patient preload dependent. And what I'm saying is that if we give nitro to a patient with a positive V4R with
30:14 right-sided heart problems, we can dramatically reduce their cardiac output because we're dropping their preload when we give Nitro. Now over the years this has become very protocol dependent and a lot of agencies are even out there saying hey if you go ahead and give enough fluids if we're very cautious with the patient's pressure you can give a little bit of nitrates while treating a patient with an inferior wall STEMI but if you're a student and you're sitting for the national registry careful don't give that patient nitro those tests are often looking to see that the student understands that nitro can be problematic for a right-sided heart problem. So remember, whenever you have a patient that has an inferior wall
31:01 STEMI, we need to look at the right side of the heart. We don't have to do this for any other STEMI of the heart, just the inferior wall. Next, we're looking at a lateral STEMI. STEMI found in leads B5 and V6 and or leads one and AVL. In the following example, look at the reciprocal changes in the inferior leads. Let's take a look. So now before I make this photo even larger, what I want to do is I want to look at where are the J points that are higher than the isoelectric line. And if I looked at this ECG from left to right, which I like to look at my ECGs that way, immediately lead one is jumping out of the page. Completely jumping out. Look
31:46 at AVL. If I see SC segment elevation in lead one that that's that crazy immediately my eyes are going to go to AVL and oh my gosh massive right now is there any other contiguous leads with one and AVL. Well, yeah, of course V5 and V6. V5 I have ST segment elevation. V6 I have possibly one box. Hard to tell with these small images. I can go and blow it up, but yeah, we definitely have a STEMI going on here. Okay. Now, if you know anything about ST segment elevation in the lateral leads, we know that there is a possible reciprocal change and that is going to be in two three and AVF. Let's take a deeper look. Now, one thing that I want you to always understand whenever you're looking at 12 lead ECGs,
32:32 always look at this bottom lead. Whoever printed this strip was also looking at lead V1. Okay? So, it's not common to see this. Most commonly, we're going to see lead two down there, but whoever again made this strip, they put lead V1. So, don't let that throw you off. Technically, we can go ahead and just like not look at this bottom line, and we're just looking at the 12 lead above. So, again, we're looking at lead one and AVL. We see that massive SC segment elevation. Let's go and look at 2, three, and AVF where we can see some pretty significant SC segment depression. Now let's see if you remember ST segment depression has to be greater than what we know it's two or
33:18 more contiguous leads but if you said 0.5 mm or more you're right which I can even say probably lead two even has SD segment depression uh but look at three in AVF massive SD segment depression so what does that mean for us that is a confirmation that this person is having a STEMI treatment for lateral wall stemmies includes aspirin, nitro, oxygen if the patient is hypoxic. I will always say that and analesics. Now we are getting pretty good at determining what is a STEMI. Am I right? Let's go and take a look at what some impostors look like. Starting off with paricarditis. This is inflammation of the paricardial sac around the heart. The paricardial
34:06 sac not only protects the heart but it allows that heart to expand and contract without much friction. This is commonly seen with a fever or due to an infection. That is huge for me. Right? If I'm a responder, if I'm somebody taking the test on the National Registry and I see a patient that has a fever, they're sick, they recently had a surgery, whatever the case is, I need to start thinking, could this patient have paricarditis? Now, if you look closely, there's a lot going on in this 12 lead. My eyes go to lead one and AVL. Not much. There's a little bit of that concave dip there. It's very minor in one and AVL at least from this photo.
34:53 But then my eyes go down a two three in AVF and whoa we have elevation. But look at it's like a halfpipe. What I want you to do is when we see 23 and AVF, remember we always look at reciprocal change. We should be seeing ST segment depression in one and AVL. We don't see that up there. Okay? We don't see any ST segment depression in those reciprocal changes. Now my eyes are going to lead V1, V2, V3, and I see what appears to be some ST segment elevation in V2 and V3. It looks very minor. Um, maybe not even meeting that criteria that we were discussing earlier, but we get very obvious ST segment elevation in lead V4, V5, and
35:39 V6. But again, we have the halfpipe appearance. So whenever I see a 12 lead ECG where there is ST segment elevation in just about every lead, I'm already a little bit suspicious. So slow down, take a step back. Your next question should say, are there any reciprocal changes? Do I notice any ST segment depression in any of the leads? If the answer is no, then I really want you to ask yourself, do I note concaved appearances? And if the answer is yes, you're looking at either paricarditis or early repolarization. Again, how am I going to differentiate the two? Well, what's the story? Does my patient even have chest pain? If the
36:24 answer is yes, my patient does have chest discomfort, then I'm already leaning towards paricarditis. I want a little bit more information about the patient, then let's go ahead and take a look at the treatment for this cuz this is interesting. Treatment for paricarditis is aspirin and fluids. Ultimately, these patients are going to require antibiotics and they have a fever, they have some sort of infection. There's something else I want to throw in here. You can lean the patient forward and that may reduce the symptoms. Sounds crazy, I know, but if you literally ask the patient to lean forward and their symptoms start to diminish, that's another diagnosis that we're looking at paricarditis.
37:11 I'm going to add this to this guide. Now, let's go ahead and take a look at early repolarization. We usually call this early repole, just for short. This is when the T-wave, which we all know is ventricular repolarization, occurs sooner than it should. Remember, I mentioned earlier that not everyone's heart is the same. Yeah, this is one of those things. And oftent times whenever I come across early repole, it's usually in a younger person and it's not uncommon that this person tells me that, yeah, people always say that I have a problem with my ECGs. I've even had previous paramedic students come through my class and they tell me that it was challenging for them to, let's say, get into the fire academy because they had to do a 12 lead ECG and
37:56 the person who did the 12 lead was telling them that they're having a heart attack at that point. What do you think that person saw? Let's go in and take a look at this 12 lead. So immediately when I look at this 12 lead, I could already see that yeah, I have obvious concaved appearances, right? Look at lead one in AVL. I don't see anything there. Lead two, I have ST segment elevation. Lead three, maybe minor ST segment elevation, but lead four, definitely we have ST segment elevation. Lead V1, pretty good there. V2 ST segment elevation. Same with three. V4 we have ST segment elevation. V5 maybe minor and V6. But you can note that we have ST segment elevation in
38:42 multiple leads. And all that's occurring is that T-wave is like encroaching on the patient's QRS complex. Like it's much closer than it's supposed to be. And because that repolarization of the ventricles is occurring early, it's going to show in a more elevated appearance on our ECG. Just because it's closer, it makes it look like there's ST segment elevation. And often times these patients don't even have a complaint. Maybe this patient is an asthmatic patient and I'm treating them for their asthma and we decide, yeah, let's go go ahead and do a 12 lead just to rule it out. And then all of a sudden I see early repole or I see this ST segment elevation. Typically I will ask, hey, do you have any other symptoms other than the shortness of breath, maybe any chest
39:29 discomfort, anything like that, and they tell me no, no, no. This is usually when I could rule in or out. Yeah, this is definitely early repole. Don't forget to always assess for that core body temperature just to ensure that the patient's not having a fever. So we could rule out paricarditis. Just like the others looking at treatment, there's none. Just treat the patient's symptoms, whatever they're complaining about. Now, let's go in and take a look at conduction disturbances. And the first conduction disturbance that I'm going to show you is the worst one. All right, we call this left bundle branch block. It states here, it's a conduction delay in the left bundle branch. Who would have thought? Widening the QRS. By the way, both conduction disturbances left and right cause a widening of the QRS complex. There's an
40:17 increase in duration, hence why it's a conduction disturbance. QRS wide and downwardly deflected in lead V1. This is a STEMI impostor. Upward deflection seen in lead one, AVL and V6. Now, let's go ahead and look at left boner branch blocks. And this one's kind of a fun one to go over with students, especially when students are like, "I don't understand the difference between left and right." Once you start googling left bund block, and you start looking at them after I talk about these rules, you're going to be like, "Oh my gosh, it's so easy. It's so obvious." Let's talk it over first. Now, whenever I'm talking about bundle branch blocks, my eyes always go to lead V1 through V3. It
41:04 just does cuz that stuff jumps out of the page, right? Take a look at V1 through V3. What do you see in that Jpoint? Uh, massive elevation. Am I right? But what do we note about the deflection of the QRS complexes? Down. Not just down, we also have like really high amplitude. And what amplitude means is the length of that QRS complex. Another thing that's very commonly seen in left bundle branch blocks. So the first thing I always want to ask and the first thing I always ask students is look at V1 through V3. Are they in an upward deflection or are they in a downward deflection? If the answer is a downward deflection, my next question is
41:50 are they narrow or are they wide? And if you know the rules of narrow versus wide, you know that 111 means everything. Right? So, it needs to be less than three small boxes. Now, if this discussion about boxes is very confusing to you, that means you don't know a lot about ECG paper, and that could be a problem. Maybe you shouldn't be trying to learn about 12 lead ECGs. But each small box is 04 seconds when I'm looking from left to right. So, if it's three small boxes or more, it's considered wide. Hear me out. If it is negatively deflected and wide, we're looking at a left bundle branch block. And all my eyes need to go to is lead V1 to rule it in or out. So
42:37 what I'm looking at is I'm looking at the distance between the start of this Rwave here to the beginning or the change in direction right here. And I'm looking to see the distance between those two points. How many small boxes are in between those two points? If it's three small boxes or more, it's considered wide. Now, the next confirmation is one AVL and V6. And all I'm looking for is there an upward deflection in the QRS complex. Let's take a look at them. Starting off with lead one, I have an upward deflection in the QRS. Looking at AVL, upward deflection in the QRS. Let's take a look
43:23 at V6 upward deflection in the QRS. That's a confirmation we're looking at a left bundle branch block. Now take a look at treatment. It states here there's no treatment for a left bundle branch block unless the patient is complaining of chest pain. This is a possible STEMI. Now there is a test called the scarbosas criteria. And this video is not the video that I'm going to be teaching you a scarbosis criteria. But understand something. If you ever come across a patient that has a left bundle branch block and they're complaining of chest pain and they're sweating and they look like a patient that is having a STEMI, call it. Do you understand what I'm saying? There's a ton of organizations that are out there
44:09 now that have gotten bit by transporting patients with left bundle branches and not calling STEMI and then having to transfer that patient to a Kath lab. If it looks like a duck, if it quacks like a duck and it's a left bundle branch block, could be a duck, could be a STEMI, send them. Now, this discussion is not to change your protocols. This discussion is just to show you how can I as a paramedic or as a healthc care provider confirm and see a left bon branch block on an ECG. Now all I did here was I just typed in left bundle branch block ECG on Google. I recommend that you do this and just look through how many ECGs have this widened down appearance in lead v1 and then look at lead one AVL and V6 and tell yourself,
44:57 hey, does it meet the criteria? Once you get good at this, you'll never miss a left bundle branch again. Next, let's go ahead and take a look at right bundle branch block. This is a conduction delay of the right bundle branch, widening the QRS. Again, there's a delay. QRS is wide and upwardly deflected. Now, in lead V1, we call this a bunny ears QRS. There will be a downward or slurred Save seen in lead 1, AVL, and V6, which we're going to get to. But what I want you to get really good at is being able to tell bunny ears, also known as terminal Rwaves. So now again coming back to lead V1 through V3 whenever I see something that looks different it stands out to me
45:45 right and when you look at this I can easily see that there's some interesting notching going on there in lead V1 even in V2 and then V3 is like crazy bunny ears right we can easily see that there are two Rwaves again we call this terminal R my next question to you by definition of a rib bonal branch block is Is it an upward deflection or is it a downward deflection? And whenever we look at these Rwaves, even if there's two Rwaves, we count them as one QRS complex. Is it greater than three small boxes? If the answer is yes, it's considered wide. And if it's an upward deflection wide with these bunny ear appearances or terminal R appearances,
46:32 we're looking at a right bundle branch block. Now, how do we confirm it? Look at what it states above me. Downward or slurred S-wave seen in lead one, AVL, and V6. So, my eyes are immediately going to lead one and AVL. Now, I understand if slurring of the S is not something common that maybe your instructor talked about. Take a look at that S-wave and lead one. We can all agree that weird notch appearance at the bottom there is not normal whenever we look at an S-wave. So, we can obviously see slurring in lead one. Lead AVL not so much. I'm going to be honest with you. There's almost like there is some S-wave in lead AVL, but it's not as distinctive
47:19 as it is in lead one. And that's okay. Coming over here in lead V6, we can see that there is that weird notching appearance that's occurring here in this S-wave. You can see that it's like going up towards the isoelectric line, then it makes a quick turn in one direction and then goes back up again. That is slurring. That should never happen. It should just be a clean line all the way up to that isoctric line. So, different things to consider. Now, I did the same exact thing that I did earlier. I just went on Google. I type in right bundle branch block ECG and you can scroll around and we could start to see these terminal R waves and an upward deflection. My eyes are immediately going to go to one AVL in V6 and I note slurring of S-waves.
48:06 And that's all I do to get really comfortable or really good at looking at ECGs and being able to diagnose them quickly is practice. Right? If you know the rules of these ECGs, it's going to jump out of the page at you. But you got to understand the rules first. Now, if you remember earlier in this video, I mentioned that there was something called LVH, left ventricular hypertrophy. LVH is another STEMI imposure that I think is a little bit more advanced for the provider. Now, maybe you work out in the field and maybe you might be a little bit interested in this, but I don't think this video was intended to diagnose the LVH. This video is intended for newer providers to practice and know the rules
48:53 on how to read a 12 lead. Now, I mentioned to you earlier as well that I had an announcement. So, if you made it this far, awesome. Thank you for sticking around and I really hope this video helped. Did not only this presentation, but did these kind of like slides and images, did they help you? Did it make it make sense? Did it cut through the fluff? If you go to paramedic school or you're in any type of school, you know exactly what I'm talking about, the fluff. When you're reading a textbook and there's so much information, just tell me what I need to know. Well, I made this. This is my guide. I wrote all this. I created these different pages. And believe it or not, I created my own book. This book is going to be available to the public very
49:39 soon. And these pages belong to that book. So if this information helped you and you want to know more, that book is literally a toz, the entire paramedic program in one book, no fluff. I also made a book for EMT as well. If that is something that interests you, please let me know in the comments if you would be interested in purchasing a book. I put a ton of hours, not just hours writing the book, but believe it or not, videos of me teaching out of the book are all in the book. They're QR codes. You just snap a photo of it and then you have a video just like this one of me explaining the content.
50:25 Now again, if that's something you'd be interested, let me know down below in the comments. Now, some of you might be asking, "Mike, I want more. I need to get better at reading 12 leads." My next step for you is practice 12 leads. The more eyes that you get on 12 leads, the better and get good at knowing what normal is. We talked about looking at that isoelectric line. I talked about putting a credit card up at that isoelectric line and seeing, hey, is there anything above that isoelectric line? Is there elevation? Is there depression? Getting good at seeing what normal is really helps diagnose when something is abnormal. I hope this helped. Let me know if you have any questions and I'll see you again on the next
