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Welcome to the last session of our Doctor's Guide series - an ECG Master Class led by Doctor Turia Khan. Doctor Turia Khan is a medical graduate from Texas College of Osteopathic Medicine in Fort Worth, Texas and has completed her Emergency Medicine residency at Western Michigan University. Today's session is sponsored by MD U and has been approved by the Royal College of Surgeons Edinburgh for an hour CPD. During the session, Doctor Turia Khan will lead a comprehensive talk on ECG Basics. She will go over the importance of finding a system that works for you, as it can help with quickly reading an ECG. She will also cover topics such as rhythm, axis, intervals, rate, and more. At the same time, Doctor Turia Khan will also provide helpful pearls and tips when reading an EKG and the signs of ischemia. A helpful Q&A session has also been arranged after the talk. Join us for this unique learning opportunity!
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Identifying deteriorating patients is a key element in a patient safety programme. But the response to them is just as important. Managing emergencies can be difficult for healthcare professionals.This series of 1-hour sessions will cover emergency scenarios within several medical fields, helping medical professional’s deepen their understanding, and master patient management.

Over the next 12 weeks, we’ll be diving into numerous case studies and scenario-based assessment in the following specialities:

  • Orthopaedics
  • Endocrinology
  • Emergency Medicine
  • Radiology
  • Spinal/Oncology
  • Cardiology
  • Obstetrics & Gynaecology
  • Urology
  • Gastroenterology
  • Anaesthesiology
  • Psychiatry
  • Paediatrics

This Webinar series will offer an exploration into critical care within these fields. Participants will be actively encouraged to pose questions as well as offer their experiences of what has worked or not worked in addressing problems. The aim is to provide a forum for exchanging ideas and practical solutions.

Learning objectives

Learning Objectives: 1. Describe the rate, rhythm, and axis of an EKG. 2. Calculate the PR, QRST, and QTC intervals on an EKG. 3. Identify signs or indications of ischemia or infarct on an EKG. 4. Analyze the relationship between EKG results and various heart conditions. 5. Make distinctions between pericarditis and an ST elevation myocardial infarction.
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Computer generated transcript

The following transcript was generated automatically from the content and has not been checked or corrected manually.

Hello, everyone. Can everyone hear me? Can everyone come and see me clearly? You can write on the chat box. Ok, so, hi Ron. Welcome to our last talk of the doctor's guide series where today we'll be having a talk on an ECG master class led by Doctor Turia Khan. Um just say a few words about Doctor Turi Khan. Um she has completed her medical school at Texas College of Osteopathic Medicine in Fort Worth, Texas. After medical school, she completed emergency medicine residency at Western Michigan um University. But now she practices as emergency medicine at UN C Johnston Health Smithfield and Payton emergency rooms in North Carolina. Um I'd also like to say that today's talk is sponsored by the MD U and it's one hour CPD approved by the Royal College of Surgeons Edinburgh. So uh just without a photo, I'll hand it over to you. Ok. Hi, everybody. Ok. So we will get started. So, um I'm trying to keep this lecture as, as focused to kind of the basics of um EKG S that you might encounter in the emergency room. Obviously, there's a lot more detail to it and there's a lot more that's gonna go into what we're discussing today. Um but this should hopefully get you guys through most of it, ok? Um We can go to the next slide, ok? I don't have any disclosures. I don't have any affiliations, ok? So EKG basics just kind of running through some of the important things. Um you can go to the next slide. Ok? So the first thing that I'm gonna say and this is gonna apply to kind of everything that you're gonna do in medicine with regards to um evaluation and things like that. But with the EKG find a system that works and stick to it. So if you're the type of person that needs to have a skeleton approach and a system, make sure you just follow that every time and then you'll kind of build a pattern and you'll be able to read EKG S very quickly cause you're gonna follow that pattern. Don't try to like jump around and see, hear something from somebody else and then be like, you know what? Actually let me try that cause you're just gonna confuse yourself if something works for you stick to it. Um So this rate rhythm access intervals. That's kind of my way of reading EKG S at least in terms of basic stuff to get started. And it's a good skeleton that I think you're gonna see in a lot of EKG guide, um websites, books, videos. Um It's just an easy way to just a approach, an EKG that can be daunting um when it comes to clinical practice, um you will want to always compare to a prior EKG if you have one. Um especially when you start to get into people with um bundle branch blocks and you know, elderly people with prior ischemic, you know, insults to their heart, they're gonna have some chronic changes. And so if you don't have a prior, then sometimes that can be difficult to determine if that's chronic or not. Um And then just a little other pearl when it comes to clinical practice that you guys will hopefully start to experience soon is that um sometimes your EKG may not show pathology early on. I've seen several times in, in practice that, you know, somebody will come in with crushing chest pain. You'll think that they're having a heart attack and their EKG won't really meet criteria just yet. And so just don't be afraid to repeat that EKG every 15 minutes every 20 minutes. And sometimes you'll start to see that the EKG will have dynamic changes and you'll start to actually see the pathology start to show up on that EKG. We can go next. OK. So um kind of a, a very brief breakdown of um reading an EKG. So of course, the first thing with the rate. So how fast are you going? Are you going normal, which is, you know, 60 to 100. Are you going slow. Are you going too fast? Um When you're looking at a rhythm, it's gonna basically break down to, is it a sinus rhythm? And is it not a sinus rhythm? OK. Sinus rhythm is gonna be something that originates at the sinus node. So the S A node um and so you're gonna see a P wave before every single QR S as long as it's beating through the sinus. Um If it's not, then you're not gonna see that P wave or it's gonna be very irregular and that's gonna tell you that it's somewhere else from the sinus node. Um And then you're gonna look at axis. Um So that's gonna be, we're gonna discuss that a little bit further on how to read an axis on EKG S. Um your basic intervals for EKG. So your PR interval is gonna be from the start of the P wave to the start of the R wave. So if you can see, I don't know if you can see my mouse moving. Maybe not. Um But the start of the P wave on that line on that box there going to kind of right after the Q wave dips down is the start of the R wave. Um Your QR S complex is gonna be from the start of the Q wave to the end of the S wave. Um your QTC. So your QT is gonna go from start of the Q to the end of the T wave um QTC is kind of a um it's an algorithmic equation that changes the QTC just cause it's a little bit easier to understand. Um But just for the basics of the EKG, just the QT just know how to calculate that. OK. Um And then, you know, looking for any signs of ischemia. So, are you gonna see any ST depressions, any ST elevations? Are you gonna see any T wave inversions or flattening or things like that? That could point towards signs of ischemia or infarct to the heart? Um ok. Yeah, so just basics, we kind of touched on this a second ago. So your normal is gonna be between 60 to 100. Um Anything less than 60 is considered bradycardic or slow, anything faster than 100 is gonna be considered tachycardic or fast? Ok. And then we talked about, you know, the rhythm whether it's sinus or not and we'll delve into that a little bit deeper later. Um So access is important. Um I try to include some diagrams just to help make it easier. So, um the way that I kind of do it, there's, you know, these go actually calculating it where you go from, you know, 0 to 90 90 to 1 80. Um ok, sorry I don't, I'm gonna try my best to try to describe where the pointer is. Um I can see my pointer. Ok. I'll I'll try and direct it. Ok. Um So um the, the easiest quick way that you can do access interpretation on EKG S is. So, um if you do one second, let me refer to my note here real quick if you go um one and a VF on an actual EKG. Um So one, so your left thumb and this is something you guys can practice while you're looking at the screen as well. So your left thumb is one. OK? Lead one and EKG and your right thumb will be lead a VF. OK. Um And so this will coincide with what I'm about to show you um on this diagram here that has the axis kind of labeled out. So if your, your overall deflection, so your average deflection of your QR is, is positive and lead one, your left thumb is pointed up, right? If your lead uh A VF deflection is overall positive, then you got two thumbs up, right? So that's normal. OK. Um The next one would be so if it's positive in lead one and then negative and a VF then kind of the axis turns to the left. OK. So a very quick and dirty way of saying that that's left axis. OK. Same concept for if lead one is negative and lead A VF is positive, then it's gonna lead to the right, right. So you got your right axis deviation and then if they're both negative, that's your extreme axis. We worry about that. We don't like extreme negatives. OK. And so very quick and dirty way. There are some things that aren't gonna always follow that and that's something that's gonna be a little bit more advanced than the purpose of this lecture. There is a question, how do you differentiate stemi from Wellens in an elderly female with diabetes and neuropathy shows deep inverted T waves and the V two and V three and could be indicative of stent stenosis. Uh hang on. OK. So there you're basically asking how you differentiate NSTEMI from Wellens when you have the deep inverted T waves and leads B two and B three. Is that kind of the, the general point of the question? Um So if I'm understanding it correctly, so Wellens is gonna be just deeply inverted T waves. Your NSTEMI is gonna have ST depressions as well. Um And it, you'll have a prior EKG for comparison as well. And then in a proper history, it'll make sense. It's hard to kind of just justify just based off of like criteria, but usually your Wellens syndrome will be a deeply inverted T wave. Your n you will have some type of ST depression along with it if that answer the question. Mm OK. Or can T wave flips suggest myocarditis. Myocarditis is very difficult because it can present with all sorts of EKG changes. Um You're not going to see one specific thing. It'll be something between um uh ST elevations, you'll see sinus tachycardia, you'll see arrhythmias, you'll see wide and QR S it's just gonna be honestly, what portion of the heart is affected by the inflammation that you're gonna see changes. And so I can't say that there's a specific thing for myocarditis. Ok. Any other questions before we move on? Ok. Um we'll, we'll grab the questions after. Ok. And the patient with preexisting pericarditis, how can you ensure a new A CS is not missed further to checking for troponin changes? So, pericarditis, that's kind of the, so the the characteristic thing is you're gonna have ss t elevations everywhere, right? If you're having an ischemic change like a stemi on an EKG from A CS, you're gonna have contiguous EKG changes. So you should not see ST elevations across the entire EKG in the setting of, of ischemia. Um That's one of the very specific things to pericarditis. If you see it everywhere. I it's likely not an ST elevation M I it's probably more likely pericarditis and then you'll also see some of the uh pr depressions and a VR pr elevations everywhere else. Um Yeah, I think that's and pericarditis may not always have, I mean, it depends you some severe cases of pericarditis can have elevated troponins, but you don't always see that with an ST elevation M I, you will likely see that. Ok. Um I'll come back to some questions in a second just so we can kinda get through the basics. Ok? Um So looking at the bottom portion of the picture. Um zib if you can try to keep along with the pointing here is um so one important thing to notice is how to calculate the size of the boxes on the EKG. OK. So an entire giant box that's encompassing the full small four, there's five smaller cubes in there. So the entire horizontal width is 0.2 seconds. OK. And the or also 200 milliseconds, sometimes it's easier to just go based on milliseconds cause the numbers are easier to remember. Um And then the entire length of the box all the way up. So they're counting two boxes here as 10 millimeters. If you cut it in half, it's five. OK? Meaning that each small box encompasses a millimeter um height in the vertical distance. OK? And so this is something that's important for you to know because you're gonna be calculating your pr intervals, QR S and QTC from the horizontal boxes to determine the durations of those and then your ST elevations and ST depressions will be calculated using your vertical boxes. Um So a normal pr interval is gonna be between and I'm gonna go off of millisecond calculation just because that's the way it makes it easier for me to remember than to think of the decimal points. So um a normal pr interval is 100 20 to 200 milliseconds. OK? Anything greater than 200 is considered prolonged, you'll typically see that in cases of your heart blocks, um some drugs can do that. Um Sometimes with some electrolyte abnormalities, you can see that as well. Um shortened is, I'm sorry, I, that was a type O on my end. That's less than 1 20. OK. And so your, you know, Wolff Parkinson white WPW pre some other preexcitation syndrome, some junctional rhythms, you'll have it shortened. Um But just as long as you remember, 1 20 to 200 there's no, I don't have a mnemonic for it. It's just one of those things you'll just unfortunately have to commit to memory. Um QR S duration, normal is 100 20 milliseconds, anything greater than 100 20 is considered wide. Um And then Q TC normal for males is 450 milliseconds, normal for females is 470 anything greater than those is considered prolonged. OK. We can move on to the next one. Um So when it comes to ST segment elevations for looking at um like specifically um ST elevation mis um the criteria. So, um I don't know if it's gonna be the same for you guys based on your cardiac organizations, but here for the American Heart Association, um theirs is you have to have one millimeter ST elevation and two contiguous leads, meaning two leads that follow a coronary distribution um in all leads except V two or V three in V two or V three. It's gonna be these numbers that are based on age and gender. So females of all ages, it has to be 1.5 millimeters or higher in males. Less than 40 greater than 2.5 millimeters. And uh sorry, yeah, less than 40 greater than 40 is two millimeters. And then um ST depressions is at least a millimeter or greater. Um Jemaa, are you asking you mean QTC? Um So that's your QT interval, but there's an equation that they used to calculate as a corrected QT interval to account for some changes with regards to the EKG. And so QTC is, it tends to be used more frequently um for the purposes of the EKG lecture today, we're just gonna stick to just QT interval. But QTC is something that we talk about a lot when it comes to like toxicology and overdoses and electrolyte abnormalities. Um But that's a little bit beyond the purpose of the lecture today. OK. So now we're gonna get into some of the must know rhythms. OK. So these are some of the things that as long as you know, these, you'll be able to read or at least interpret most EKG S that you'll come across of or they'll fit something within this pattern. There might be some changes here and there, but this is at least in terms of the most common. OK. So we're gonna kind of break it down starting with the rate. OK. So you're gonna break into either your normal, which if you have normal, there's not a whole lot that's gonna change. You might have like a premature ventricular contraction or something every now and then. But there's really not a whole lot to go into it. So I don't have a dedicated slide to that. Um For your bradycardia, it's gonna break down into, um your, most of them are gonna be your sinus bradycardia, meaning you've got a P wave before every QR S. So the bradycardia is originating from your SS ay node. Um And it'll be less than 60 BPM. Um You will see a lot of sinus bradycardia that are not pathologic and so a lot of the young healthy individuals, athletes, um even some people who are just have a genetic predisposition to having a low heart rate. Um You'll see that as a sinus bradycardia on their EKG and they will be not symptomatic from it. So that's gonna be your key to a lot of your sinus bradycardia is whether or not they're symptomatic. Um And then the heart block. So first, first-degree you typically won't see bradycardia. I just put it in here just for completeness of um discussing heart blocks. Um So your first-degree heart block will be apr interval. That's over 200 milliseconds. So it's a prolonged pr interval. Um It's a prolonged pr interval, pr interval, excuse me, with everything else that looks about the same that it would on a normal EKG um second degree heart blocks breaks, breaks up into 22 types from the Mobics. OK. Mobics type one and Mobics type two. Mobics type one is, you'll, you'll see that the pr interval is gonna gradually elongate until you're gonna have a dropped QR S beat. So it's gonna be one that will look normal. The next one will be a little bit longer, next one will be a little bit longer than that and then you'll have a dropped beat. Um And then the Mobics type two is that you're gonna have a persistent or same length of the pr interval from beat to beat. And then there's just gonna be a randomly dropped QR S OK. Mobics type two can sometimes present with bradycardia depending on how, how frequent you're having those random dropped beats. Um And then third degree is complete pr or P QR S dissociation. So the, the Atria is beating completely independently from the ventricle. OK. And so, um that's gonna be most of your bradycardia that you're gonna see that are not sinus will probably be a third degree. Um The easiest way to and when we get to it, the I'll kind of describe the easiest way to calculate it just cause third degree, a lot of the times people can present with a Mobics type two and a third degree that it's confusing to differentiate which one's which and it'll still continue to be difficult. And that's when you kind of loop in some of your cardiologist to take a look at it as well. Um Will they get a copy of the presentation? Yes, I was just about to answer that one. Yeah. Yeah. Ok. OK. Yes, you guys will. OK. We can go to the next slide. OK. So here's a practice EKG if someone wants to, to take a, a go at it, you can post your, what you think the rate and rhythm is in the comment box. OK. Do you have a number six big boxes between be so about 60. Yeah. 51. OK. So this is actually bradycardic. OK. OK. Good. Yeah, so um so kind of go down the system, right? So rate, rhythm axis intervals. So um the easiest way there are two ways that you can calculate rate. OK? Um One is so if you go to the very bottom of the EKG and the rhythm strip that's marked as two. So they're grabbing that rhythm strip off of lead two. So an entire rhythm strip on a, a single printout of an EKG is gonna span 10 seconds. OK? If you count the number of QR S beats within that time, then that'll give you eight and you multiply it by six to give you a full 60 seconds. OK? So then that gives you about 48 BPM or 50 you know, give or take um uh a couple the other easy way to do it. And I think this is the way a lot of you guys are doing it is. So if you find a QR S that lines up perfectly on one of the vertical lines, one of the darker vertical lines on the EKG, you count backwards, I count backwards. Some people count forwards, you count backwards from that QR S. So the immediate box, right? Or the line right after is 301 5175 60 then 50. So it kind of falls right along 50. OK. So that rate is slow, right? Less than 60. So that's slow. And then you look to see is it, what's the rhythm? Is it sinus or not? So you look and see that there is a P wave before every single QR S OK. And it looks like they all kind of beat along a, a general normal interval. So they're all regular. So that's a sinus bradycardia. OK? And then um here's a good one if somebody wants to take a whack at this and see what is the axis on this? EKG good. OK. It's normal. So um just to kind of go through the thumbs up, thumbs down thing that we were talking about. So we said one in a VF, right? So one is your left thumb. A VF is your right. OK. So the general deflection of the QR S. So you kind of go based off of everything on your isoelectric line, how much of it is above and how much of it is below, right? So the general du deflection on this is positive because that QR S is all above the isoelectric line. So that's positive in your left. OK. And then a VF you've got a small S wave there, but really the R wave is a lot stronger on that. A VF so it's a general positive. So it's a normal axis. OK. OK. Do we have any questions before we move on? Yeah. OK. All right. So first-degree a block, the, the calc of the axis or the, the rate? OK. Um So curious to Q Yeah. So um Zib could you maybe try to point along with this um if you go to the very bottom of the EKG that rhythm strip of the um lead to the continuous EKG rhythm, if not, we can do from the right most on that rhythm strip on the bottom. If you go one QR s over to the left, that one, all the way at the bottom. Yeah. All the way at the bottom. Yeah. And then there's the um the QR s that's the second from the right. Um That one lines up pretty well right on the dark red line that I was talking about. So each dark red line, meaning each giant box moving back, I'll explain it next Neli. OK. So each dark line is gonna coincide to a number. OK. Like a general idea of the rate. OK. The first one immediately a immediately prior to that QR is 300. Correct. Next is 1 50. The one after that is 100 the one after that is 75 then 60 50. OK. Yeah. OK. So then um going back to the axis calculation with the thumb rule. So left thumb is lead one. OK. Right thumb is a VF OK. If you're normal in both, meaning your general deflection of your QR S is either positive or negative. OK. So looking at this specific EKG and lead one, your majority of your QR S is above the isoelectric line. OK? You see your R wave is all the way positive, there's really nothing negative. OK? So that means you have a positive deflection. So your thumb is pointing up cause it's positive. OK. A VF there looks like there's a small little dip of the S wave but still overall, you've got a positive deflection on that. A VF of the QR S OK? So thumbs up on, right. OK. So two thumbs up is normal. OK? And then just to kind of, well, the some will work for all it will work for most of them. OK? You might have some that aren't gonna always point towards that. In which case, you'll have to go to a little bit of more complex calculation with one in a VL. Um And so just the quick and dirty is one in a VF. Um So two thumbs up is positive. If it's positive and one negative in a VF, then you're gonna be leading left cause you're thumb up is gonna lean that way. So you've got left axis positive in a VF negative and one, you've got right axis, two thumbs down is extreme axis. OK. OK. Um Does somebody wanna calculate the pr interval on this one? Good, good. So we're either somewhere between 3 20 to 3 60 milliseconds. So it's prolonged. Um So you wanna start at the start of the P wave. So the very beginning where that P wave um deflection is and you're gonna count the number of boxes all the way to the end or the start of the R wave. And that's gonna give you eight boxes, eight boxes times 40 milliseconds is 320 milliseconds, right? Good job. 3 20. Does everybody see that times 40? So remember each of the small boxes in between the dark lines, each of the small little boxes on the horizontal distance is 40 milliseconds on the horizontal distance. And so an entire dark box like the box outlined by the dark lines is 200 milliseconds and there's five little ones in each one. So 200 divided by five is 40. You're welcome. Um So you see, so we know that the pr interval is belonged, but then we see that there's a P wave before every QR S and this is not a perfect EKG. I'm sorry, I should have probably found a better one here, but it's gonna be a normal rate. Ok. And we can probably calculate that with that. You know, the backtracking QR S method 301 5175. So it's about somewhere between 60 to 75 8 boxes to. Yes, correct. Um And so it's a normal rate with a regular rhythm. Your pr interval is prolonged and so that fits the diagnostic criteria for first-degree A V block. OK. OK. We can go to the next slide. So here's the difference between your first and or your second degree Mobics type one also called winky back. OK. And Mobics type two. So if you can see and you can probably calculate this, if you can see those small box is big enough. But if you look at the top EKG strip, you see that the pr interval from each consecutive beat is prolong, gradually elongating and then you have a dropped QR S so it drops the beat there. And so these can present with some bradycardia again, depending on how frequently that's dropped. Um But uh generally in, in most of the ones that I've seen, they tend to be kind of normal or low normal. And then if you look at the EKG below, you see that between beat to beat, the pr intervals are constant, but it's just randomly that one gets dropped, there's no specific pattern. OK? And then third degree. So this is where I'm gonna, I'm gonna show you how to calculate it and if you have a paper with you, um it might help. Um let me grab one too so I can calculate it with you. Next second. I don't have a pen here. But what you're gonna do is grab some blank paper. This is gonna be what we call a, a poor man's caliper. Um where I practice. So you're gonna put your paper up to the P wave um on that first uh beat on the left and you're gonna put a tick mark next to the next consecutive P waves. OK? And when you kind of like measure it out across the EKG, you're gonna see that the P waves are gonna always be at a regular interval. So the P waves are gonna be consistent. You might have some that are buried in the QR S. So you may not see that the P wave is there. But if you count every single one, there's gonna be a P wave with every single QR s or every single P wave, the interval is gonna be consistent. OK? And you'll do the similar thing with the QR S. And so you're gonna see that the QR S are gonna be beating at a regular interval to each other and the P waves are beating at a regular interval to each other. But what you're noticing is that the P wave and the QR S do not coincide with one another. And you can see that on some of these EKG S that on the very left, you've got one that looks like a prolonged pr interval and then you've got your QR S and then next one is APR that's maybe normal. And you've got a QR S and then you've got suddenly a P wave and then another prolonged QR S and then you kind of see on that third beat how there's a QR S and there's a little deflection there and then another which looks like another beat. So that's actually that first deflection is your P wave that's buried in the QR S complex because the Atria is beating independent of the ventricle. OK? And then if you go to that fourth beat, you see, you've got your P wave, your QR ST wave and now you've suddenly got a P wave, OK? And the way that you would differentiate between that being either the T or the P is that you do that where you measure it out and you notice that the P wave marches out every single time equally to one another. And so this is complete dissociation. So complete heart block, complete a V dissociation. And so these will tend to be slow. The reason that you're gonna tend to be slow is because if your QR S is the one that is the transmitted beat where you calculate your heart rate from the ventricle slows at a or beats at a much slower rate than the atria one. Because your A V node, it just has a slower processing, it has a slower, slower intrinsic rate. But then also you have to get that electrical conduction to go all the way down, kind of across your bundle of his pin fibers come back up and then your heart has to reset, go through that refractory period and then go back again through. And so that's intrinsically slower than the S A node. OK. And so that's why you'll see a slower heart rate with a third degree heart block. Does that make sense before we move on? Cause I know sometimes uh complete heart blocks can be a little bit difficult to understand. OK. All right, we'll move on to the tachycardia. OK. So the easiest kind of um approach to tachycardia is gonna kind of follow, it's gonna be a similar process of how you calculate your EKG. So you know, you look at your rate, OK, you find out it's fast. The next thing to do is figure out is it a sinus tachycardia or is it not sinus? OK. Um So same thing pee before every QR s if you see a pee before every QR S and they're all beating at regular, they seem like they're conducting. Well, that's a sinus tachycardia. OK? If it's not sinus, then your next step is to decide is your QR s complex, narrow or wide? And when they say narrow, they usually mean, is it a normal QR S complex in terms of the duration or is it widened? Ok. And then once you decide whether it's narrow or wide, then it's gonna further break down into whether the um the pattern or the rhythm intervals between the QR S. Are they regular? So are they all happening at a regular predicted interval or are you having kind of irregularity where some are beating faster? And then there's a slow and then beating and it seems like it's kind of all erratic? Ok. Um So you find out that you got an EKG and your heart rate is over 100. OK. And then you find out that it's not sinus. So you look at your EKG, there's not a P before A B QR S. So now next step is to look at, is it narrow or wide? Ok. If it's narrow, which is gonna be these first two that I've got listed here. Next is you look to see, is it regular, irregular? OK. If it's narrow and regular, there's usually only a handful of things that it can be the most common that you'll see will be SVT or atrial flutter. Ok. SVT being supraventricular tachycardia atrial flutter with a fixed block means that it's gonna be, you're gonna have your characteristic flutter waves and we'll get to that in a little bit. So you'll have atrial flutter and it's gonna be a consistent conduction pattern. Ok. Sometimes you'll see some where it's atrial flutter and it's not gonna be consistent and we'll discuss that how to differentiate that, but usually narrow and regular if you see that it's atrial flutter with a fixed block and then orthodromic WWPW uh orthodromic, meaning it's going through the normal electrical channels. Ok. So you've got an accessory pathway that's beating through the A V node and then back up through the accessory pathway. OK. And so it kind of follows that narrow reg QR S and then when we get to antidromic antidromic means it's going opposite. So anti meaning opposite of the normal electrical pathway. So the accessory rhythm is breaking through and coming around the opposite way. So it's going anti clockwise. OK? If it's narrow and irregular, OK. The most common that you're gonna see and this is one to just know about cause you're gonna see it, especially if, if any of you guys are looking into working in the emergency room, you're gonna see this a lot. OK? Is atrial fibrillation? OK? And then atrial flutter with the variable block is what I was talking about um a second ago. And then if we move on to where now you are going into the wide complexes. So you do your EKG it's fast. You look to see it's not sinus and then you look at your QR S and it's wide and it's regular, meaning it's beating at a regular interval. One of the most common ones you're gonna see is ventricular tachycardia. Ok. You can see the antidromic WPW is what I was telling you about a second ago. That'll have a wide complex because it's going opposite of the normal conduction pathway. So it's a slower process. So your QR S is gonna be wider cause that electrical conduction takes longer on the EKG. OK. And then you've got your wide and irregular and uh one of the more common ones that you'll see is your atrial fibrillation in the setting of some type of bundle branch block or some type of aberrancy or something like that. OK. Does that kind of make sense, straightforward kind of process to approaching tachycardias? OK. Perfect. OK. Feel free to, to pop in questions as they come up and then I'll answer them kind of as we go along. OK. So here's an example of your sinus tachycardia. Does someone wanna tell me what the heart rate is on this one? Correct? Yeah, about 1 50. I Exactly. Perfect. All right. Great. OK. So you see that it's fast. OK. And then now you look to see what the rhythm is. OK. So you see A P before every QR s and it's at a regular interval. So that is your sinus tachycardia. OK. All right. Let's move on to the next one. OK. So here is a very characteristic of what you're gonna see with your supraventricular tachycardia. OK. So you can see it's very fast just looking straight at the EKG. OK. Um And then you look at your uh rhythm strip and you see that there aren't any obvious P waves, OK? You see your QR S, you see kind of an upward deflection after that you're like, maybe that could be a T wave, but it could also be a P wave. And so it's not 100%. OK. So now, you know, this is not a sinus rhythm. OK. So next, after you figure out it's fast and that it's not sinus, you have to look at the QR s decide if it's narrow or wide, right? And looking at this, it's kind of too small to calculate just cause the picture may be, the boxes aren't very visible. But once you see um EKG S enough, it's, it's very obvious that this is a narrow QR s, right? It's like just a straight line. OK? So that's narrow. OK? And then you can see that if you kind of do the same poor man's caliper, unless if you actually have Calipers, you're welcome to measure it that way. But you can see that every s single QR s follows a regular interval. You can see that it nearly beats every single one on one of those dark lines. OK? So it's a regular interval. OK? So that's a tachycardia. That's not sinus, that's narrow and regular. OK. And so this is your supraventricular tachycardia. OK. Now, one thing when you get to clinical practice is sometimes you'll see atrial fibrillation with what we call aberrancy. So it's an aberrant conduction pathway can present looking similar. OK? A caveat and this is why I kind of mentioned this usually over 1 80 BPM above. Is that set when you see it is gonna be very, very fast, OK? Like you're gonna get heart rates in like the two hundreds. OK. Good. Whoever mentioned the right axis good. Um So it's gonna be very, very fast. SVT like I've seen upwards of two, sixties, two seventies. OK. Atrial fibrillation with aberrancy is gonna be slower. OK? So it's gonna be somewhere around like 1 50 to 1 60 but it's gonna look like SVT. So that kind of can be your little bit of your clue that it might not be SVT. You can see SVTS that slow and there's some blocks going on, but usually in most cases that rule of thumb will get you through majority of your EKG S. OK? And so this is your SVT. OK. Let's go to the next one. OK. So now we're getting to our narrow and irregular. OK. Could I repeat um about the, the difference between SVT and AFIB with aberrancy? Is that what we're asking? Explain axis in this? OK. Let me answer uh Doctor Danielle's question first and then I'll answer you after that it's OK to, so, um the, so SVT is gonna be faster, it's gonna be very fast. So generally the general idea is if you are beating over 100 80 BPM with an EKG, that's fast narrow and regular, most cases are gonna be an SVT, ok. Atrial fibrillation with aberrancy is gonna beat slower than that. So generally you're gonna have somewhere between, you might see like 1 51 60 it's gonna be narrow and regular. Um And so that's gonna kind of point towards afib with an aberrant conduction. OK. Um For the axis on this. So, um we said, so look at lead one, lead, one is your left thumb, right? You see how that QR S is mostly pointing down. So it's negative deflection. So that means your thumb is down. OK? An A VF there are some s ways but the general deflection or the general average of that is positive, right? So you've got a thumbs down and a positive. So you're gonna lean to the direction of the positive thumb. So you've got a right axis deviation. OK. OK. So atrial fibrillation and flutter. So these are your narrow complex tachycardia that are irregular. OK. The key to, I mean, both of them technically is absence of P waves, but it's gonna be much more characteristic in your atrial fibrillation. So if you look at that top EKG, it doesn't really like, you know, some of these fibrillatory waves, quote unquote. So it's kind of the Atria just kind of quivering, right? So you're picking up the quivering activity. So that can sometimes look like a P wave, but generally it's just, it's just vibrating. Ok. And that's what the electrical rhythm is picking up is the vibrating of the Atria. Ok. It's an irregular pattern. So you see how these Q RSS they all beat at different intervals between some of them are far from one another. Some of them are close. So that is gonna be your characteristic atrial fibrillation. EKG. OK. Um And you know when you're starting on E reading EKG S and you're early on and you're not 100% comfortable with it, take out that paper and measure them out every time. OK? And then you'll get comfortable starting to recognize that fairly quickly. OK? And then um atrial fibrillation with rapid ventricular rate is gonna be an atrial fibrillation with over 100. OK. The way to calculate the ventricular rate is the same that we do in a regular EKG. You count the Q RSS on a rhythm strip multiply it by six or count. Uh Actually, you can't do the box thing because it's not gonna um correlate since it's not regular. So you have to count the number of Q RSS in your rhythm strip multiply multiply it by six. OK. And then atrial flutter, you've got your characteristic Sawtooth. So if any of you have looked at kind of a saw from the side, you see that kind of those bridges like that, that's your sawtooth, OK? Saw tooth pattern, OK? And the best place to see it cause sometimes you'll see some EKG S where they may not always have saw tooth. The best places to recognize a sawtooth pattern is leads to three A VF or V one. OK. Um And so the way that you calculate your conduction is you're gonna count the number of sawt tooths between a QR S. Ok? So if we go um from the one on the left, so skip that first QR S cause that EKG portion is cut off, you count 123 Sawtooth to one QR S. So that's a 3 to 1 conduction. Ok? So three Sawtooth to three atrial fluttering beats to one conducted QR S. Ok? And you can see that between each one actually 1234. OK. So this is an example of a variable block, ok. How some of them have three in between some have 43432. So this is what I mean by variable. Ok. That the number of atrial beats between are flutter beats. Um Could you for example of how to calculate ventricular rate? Could you please? Yeah, I'll come back to that in a second. Um So you see how the the sawtooth between each QR S is variable here? That's a variable block. Ok? And an atrial flutter with a normal and we've got examples of it coming up when an atrial flutter flutter with a, um, with a normal block or a regular block is gonna have, it's gonna be three between every or two, between every or four, between every. So it's gonna be equal between each ones. Ok? Um, when we go back to calculating a AFIB heart rates, ok, you have to calculate the number of Q RSS on your rhythm strip. So at the very bottom of your EKG, that entire long strip that runs at the very bottom is gonna be a 12th block, ok? You can calculate it across like um if you've got an EKG and it's got like you know your 123 A blavf, all of that, you can calculate it across one of those. It just gets confusing because you've got the break and the leads I just go to the one that has the continuous rhythm strip, you calculate every QR S in that rhythm strip and multiply it by six because a rhythm strip is 10 seconds long. If you need to calculate the rate per minute, then it's times six. Ok. Yes, exactly. Zane got it. Ok. Let's move on. Ok. Here are moving on to ventricular tachycardia, ok. Um I tried to incorporate some examples of some things that are um important to know on ventricular tach tachycardia. Ok. So ventricular tachycardia will be of two types, ok? You'll have your monomorphic, what that means is all the QR s have the same morphology. OK. So both of these EKG S are actually monomorphic VTAC because every single QR s complex looks exactly the same. OK. Um It's just the I I included these because there's examples of capture beats and fusion beats. OK. So, um the most important to know for polymorphic VTAC is that it's gonna be varying morphology. One of the most common ones you're gonna see in pathology is gonna be torsos. OK? And that's a characteristic of a severe electrolyte abnormality. And we'll get to that in a little bit. A capture beat is basically, you occasionally have a beat that is the S A node breaks through and beats like normal. And so you're gonna have a normal looking beat in the midst of all of this V tac. OK. And so if you look at that top EKG that circled area, you see how that looks like a completely normal EKG beat that is a characteristic of a capture beat. OK. And then you've got fusion beats. So fusion beats is basically where the sinus. So the S A beat coincides at the same time as your ventricular beat from the ventricular tachycardia and they kind of morph to create this, you know, intermediate or middle ground looking beat to both um beats that you've got OK. So on that bottom EKG, you see you've got your monomorphic VTAC starting on the left. So everything kind of looks the same and then you've got this one beat and then something that looks normal and then it kind of looks like it's decompensating back into VTAC. So what that is, is you've got a fusion beat. OK. And in this particular EKG, what probably happened was this was a, a no nonsustained episode of VTAC or they gave some medicine and it temporarily went back to sinus. So the sinus beat broke through and now you've got VTAC again. So this one shows both the fusion beat and a capture beat right next to it. But if you wanted to break them apart to visualize them separately, then you've got the top and bottom. EKG. Does that make sense? OK. So here's a great example of a monomorphic beat ta OK. So you'll have the, it looks like it's tachycardic, right? You've got a fast heart rate, OK? You don't see any P waves anywhere. OK? So this is not a sinus beat. And now you look at your QR s and it's very obvious to see that that's a wide QR S OK? So now you've got a tachycardia that is not sinus, that is wide, but it's regular. OK. Each of these beats, although it's abnormal, they're all beating at a normal interval. So that's a wide, regular tachycardia. So that's your ventricular tachycardia. OK? And monomorphic because all the Q RSS look exactly the same. OK. So here's an example of polymorphic and specifically torsos. OK. So you've got, you see how some of your VTAC beats are long, some of them are shorter. You've got kind of this like wave type pattern going on. So that's characteristic of torsos. OK. Um Torsos, literally the exact, the torsos did the points. I'm American. I don't know how to say the, the name properly. It means turning of the point. OK. So it's kind of that thing is, is turning on its axis. OK. And so this is a polymorphic because everything looks different. OK. You've got two types of VV ta beats, you've got the long wide one, you got the short wide, 11 is point down and one is point up. No, a sine wave is completely different from this. OK. A sine wave is gonna be like a wider and kind of a more cury thing. OK. But they both originate from a similar, similar electrolyte problem. OK. All right. Does this make sense to everybody? OK. Um Zib, are we gonna have time to do cases cause we're kind of coming close to the end? I'm not sure. Um We've only got about eight minutes. So OK, just quickly wrap it up, isn't it? OK. Um We'll try to see what we can get through. OK. Let's try to get through the rest of this. We're almost done with the, this part. And then we have a couple of cases that we can try to run through. OK. So um ST elevation mi I so this is, you know, your, your big bad EKG S that you're gonna see and worry about in the er OK. So like we discussed before, it has to follow two or more contiguous leads. OK. And so these two pictures at the bottom are great visuals of how to understand this. OK. Um And if you kind of, I probably should have included this but if you think about where the leads are placed, they coincide to these a arterial distributions. OK? So it's just something that you will have to try to find either a way for you to remember it, commit to memory or if you're, you know, really good at kind of correlating the EKG leads, then you know, that's the way to do it, but this is the way that I remember it is so inferior, 23 A VF OK. Inferior portion of the heart is the right side of your heart, right? Your right, your right heart is gonna be laying down on the diaphragm and so inferior. OK. So that's your RC A can also be your circumflex depending on the anatomic distribution and location. OK? Your lateral is gonna be up here. So if you look at the anatomic picture, you've got one A VLV five and B six. So it's gonna be one A VLV five and six on the EKG and it coincides to either your circumflex and you can kind of see your circumflex like wrapping around and then your diagonal branch coming down. OK. And then anterior which is V three, V 123 and four is gonna be your anteroseptal, OK? Your septum is gonna be V one and two and then anterior is V three and four. OK. So that's just kind of like a general gist of it for you to try to put that in your mind to help understand the vascular distributions. OK? And that's gonna be helpful whenever you're uh talking to your cardiologist about your ST elevation mi S and where you think the the problem is and then it, it just, it, you know, validates you whenever you look back at the Cath report and see that the ar artery you suspected was the one that was stented. Ok. Um You may see some reciprocal depressions in opposing lead. So if you kind of look at the picture, exact reciprocal of inferior is gonna be either your lateral or part of your anterior. So you'll see reciprocal depressions there, same thing with the lateral. You'll see depressions in the inferior and then anterior could be either or depending on what exactly which part of the heart can be affected. Ok? But it's not necessarily, you don't have to have ST depressions to diagnose an M I OK. Your key point there is it has to be ST elevations that follow the height requirement. So one millimeter in all the leads except V two or 3/1 0.5 in females of all ages, over two in males that are over 40/2 0.5 in males that are less than 40. Ok. And so if you see two contiguous leads, so if you see like two and three or three and a VF or you see one and a VL or V 56 or two and V three, then those are contiguous leads. OK. It's following an arterial distribution that points towards ischemia. Ok. All right, we can move on. Ok. Can somebody tell me what vascular territory is affected by this? Yes, perfect inferior. That's perfect. Correct. Ok. And you see the reciprocal depression. So you see the ST depressions in one in a VL. Yeah. Good job. Ok. So you see that it's the right side of the heart that's affected. Great job you guys. Ok, let's move on. That's fine. Just trying to get through some cases. Ok. Ok. So case number one. Ok, you have a 19 year old female who presents to the er, has a chief complaint of palpitations for the last three days. She's in the middle of midterm week, midterm exam weeks and has been drinking a lot more caffeine to keep up with those tests, say she feels like her heart is racing. What do you wanna order? Hint it relates to the lecture we're talking about. Ok. For time purposes, we want an EKG All right, let's move on. OK. OK. Good. Um What does this EKG show? OK. So we are regular. Yes, Miriam got it right. Sinus Tachycardia. OK. So go all the way down to that rhythm strip at the bottom. OK. That's gonna be the easiest one for you to read everything through. So it looks like there might not be P waves but there actually are. So you see kind of after the QR S you got kind of the double bump that is your T wave and then immediately followed by a P wave. OK? So you've got P waves before every single QR s and it's fast, it's regular. So that's sinus tachycardia. OK. Probably caffeine induced. All right. Case number two. Is there a bif P? It's not a bif P wave, it's a T wave immediately followed by a P wave. Um It's just the refractory period is fairly short on this. I think maybe one more case. OK. Let me see. Hang on. I'm gonna really quickly check on the side cause I wanna give a good EKG case then if we're doing just one more. Um uh Let's do, let's go to Case number five and you guys will have access to these when they send it to you and so you guys can practice some of them later and what my emails at the end of it. So feel free to email me if you have questions. So case number five is a 47 year old female with history of end-stage renal disease. On Monday, Wednesday, Friday, hemodialysis sent to the, er, from dialysis for syncope. According to Ems, she was getting hooked up to the dialysis when she suddenly went unconscious, lasted for a few seconds before regaining consciousness en route in Ems. So in the uh ambulance, she lost consciousness again. Currently, patient is awake and complaining of lightheadedness. She appe appears pale and diaphoretic. Um for time purposes, we want an EKG. Let's go next. OK. Can someone tell me what we see here? Great job. OK. Great job. Even further is a good job. So yeah, so we see starts as a normal si or a normal sinus or even almost an irregular, like a sinus with maybe a sinus arrhythmia. OK? And then it breaks down into what looks like a polymorphic V tac. OK. And you guys are right? It fits a toad characteristic. That's fantastic and then it breaks out of it. Yes, electrolyte disturbances due to er Yeah, exactly. So in this uh patient with ESS RD, it's likely due to hyperkalemia. OK. Um So let's go to the next slide. So suddenly the patient become, becomes pulseless and CPR is begun after defibrillator shocks, the pulses return, you start IV magnesium infusion EKG is repeated and shows this OK. Um Just for time purposes. So we've got a normal EKG. OK. So this was supposed to be a trick EKG if we had time. It's a normal sinus rhythm. OK. The caveat to this is, she's got peak T waves. OK. So if you look at V three V four, V five, you see how tall those T waves are. So those are called peak T waves. Those are characteristic for hyperkalemia. Exactly. Perfect. OK. Um Do we have time for one more or no? I mean, if they want to, why not? If you guys want to, it's up to you, it's up to them if they are willing to stay longer. Ok. All right. Ok. Ok. We can go to the next one and then we can backtrack if needed. Ok. Case number six, you have a 64 year old female who presents to the, er, with the chief complaint of lightheadedness that started today. She currently is on metoprolol and Eliquis. She is noting some chest pain and shortness of breath as well. Ok. We order an EKG and what does it show? Let's go next. That's OK. We'll give you guys a minute or so to try to interpret the EKG. Ok. It's not SVT. Um, there are ST elevations there, Doctor Daniel, I will discuss that in a second. Ok. Um, so, so Keto, do you mean which, which A f do you mean? Ok. If you guys mean af meaning atrial fibrillation. That's correct. Ok. So we look at the rhythm strip at the bottom. OK. It's fast. Ok. There are no P waves that we can make out. So it's not sinus. The complex is uh you could say it's borderline normal. Um You could say either, you know, either it's narrow or wide um and it's irregular, right? So this is a characteristic atrial fibrillation. Ok. Now, for the couple of you that picked up on the, the ST elevations and three and A VF and you do see reciprocal depressions. So the caveat to this thing that you're gonna see in clinical practice and this is gonna also go based off of story sometimes is in tachycardic situations, you're stressing the heart, right? So this is essentially a failed stress test on this patient, right? Cause now they've got ischemic changes related to tachycardia. So myself in clinical practice, I don't necessarily call an ST elevation M I off of a rapid heart rate because this seems like rate related changes. Ok. So they probably do have some stenosis in their coronaries, but this seems to be a little bit more likely, probably rate related to that atrial fibrillation. If we gave her some medicines and slowed down that heart rate and then repeated the EKG these ST elevations probably would either go away or get less. Ok. Is the right 1123456789 rate is at 1 62. That's correct. Ok. So the key giveaway to that patient specifically that this was AFIB also is um they mentioned that she was on metoprolol and Eliquis. So she was on a beta blocker for rate control and then is on a blood thinner for, um, uh, prophylaxis from preventing a clot formation in the atria. Ok. All right. Ok. Let's move to the next one. Ok. 74 year old male presents to the, er, with the chief complaint of irregular heartbeat states, he was told by his cardiologist that he might need a pacemaker in the future. Sometimes he feels lightheadedness and also is having some diaphoresis. So we get the EKG and it shows the next rhythm. Somebody tell me what we see here. We'll give you all two minutes just because it's a little bit, uh takes a little bit more when you say Winky buck. Are you mean meaning Mobics type one? Try again. It's not Mobic type one. Hm. Hang on. Maybe I put the wrong EKG up. OK? You guys, yeah, you guys are correct. I'm sorry. That is, it is a Mobics type one. It was supposed to be a Mobics type two with the pacemaker thing, but I put the wrong EKG in, I'm sorry. Um So this is a Mobics type one because of what everybody says. OK, if you look at the pr intervals, you have progressive prolongation and then you lose a QR s correct? OK. Um If these pr intervals were at regular intervals from beat to beat and then you had a dropped beat, then it was a Mobics type two. Ok. Um. All right, good job. You guys, you guys are sharp today. Ok. Um we can go back to um, case two if everybody wants to do a couple more otherwise you guys are welcome to try them yourself. I think it was it. Case two or three. Yeah, I think it was case two. Yeah, I'd say we just do case two and then up for the day. Ok. That's fine. Ok. All right. So 57 year old ma 57 year old male presents to the, er, with the chief complaint of sudden onset lightheadedness feels like he's going to pass out and feels very weak. No episodes of chest pain or shortness of breath. He's had similar episodes in the past, but they've gone away on their own. What is, let's see what the EKG shows. Perfect. Good job you guys. So if you notice, if you, this is a great one to practice, um, what I mentioned about uh marching out the P waves and the Q RSS. So if you measure it out on your paper, you're gonna see that every single P wave has a regular equal interval between one another. OK? And the QR S same thing. But they don't beat with respect to one another. So complete dissociation. Perfect. All right. Good job guys. OK. I think that's probably it right up. I mean, if they want to do the third case, they are more than welcome to, if not, they can do it on their own and then email, I think they want to do it. Let's go ahead and do case three then is all. Ok. Case number three, we'll make this the last one. Ok. Um, case number three is a 26 year old female who's 24 weeks pregnant. She comes to the, er, complaining of shortness of breath for the last three hours, having some chest tightness and pressure. Also feeling lightheadedness when she walks around, she has never had a similar symptom in the past. So we get the EKG and this is what it shows. All right. What are we seeing here? Great job. Does somebody wanna guess what the heart rate is on this? Yeah, it's close. It's probably somewhere like 2 75 to 300. Yeah. All right. I think this might be a good stopping point. Yeah.