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See Description — Ken Grauer, MD (11/26/2023)


NOTE: I have combined Video material for this 1st and my 2nd ECG session into this 22-minute video. Please note that I have completely reworked and streamlined all content — with focus on presenting the Systematic Ps,Qs,3R Approach for Rhythm Interpretation — and then applying this to the case presented in ECG Blog #220 (https://tinyurl.com/KG-Blog-220 ) on a patient who presents with a WCT (Wide-Complex Tachycardia) rhythm — 11/4/2023 —


Join Dr. Ken Grauer for the first of a four part series on ECG Interpretation!

With over 40 years teaching medical providers of all types and levels of experience — Dr. Grauer has specialized in the areas of ECG and Arrhythmia Interpretation. He has authored more than 15 books on these topics and delivered hundreds of ECG workshops.

Although he retired in 2010 from his full-time academic position of 30 years, as full-time teaching faculty in family medicine — he remains exceeding active with his own ECG Blog (begun in 2010) — as well as being a regular contributor/consultant to numerous international ECG internet forums — including over 500 Commentaries since 2018 on Dr. Smith's popular ECG Blog and 100+ more on the ECG Guru.

Dr. Grauer will begin an on-going involvement with virtual teaching in his goal of "spreading the doctrine" of time-efficient, accurate, clinical ECG and Arrhythmia interpretation.

Read the full blog post here: https://tinyurl.com/KG-Blog-220

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Please See My Description — Ken Grauer, MD (11/26/2023)

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

Welcome everyone. This is my first E CG session live on all med. I'm delighted to have this opportunity to talk with you and hopefully we'll be giving you some pointers on E CG interpretation. I'm gonna start with cardiac arrhythmias. The good news with the blog post is you don't have to take any notes because it's all here in my 20 to 30 minutes with you. I won't have time to go over everything, but all of the details are in here and you can look at that at your leisure. There's some simple basic concepts that I wanna get across regardless of the experience level. Perhaps the most common oversight is not having a system. And if you don't have a system, number one, you're gonna miss things. Number two, which a lot of people don't realize is you'll actually go faster because you're not going back and forth and you'll be more accurate. Let's just get started with a particular rhythm. A 51 year old man presented to the emergency department with palpitations that began an hour before he came to the emergency room. How would you interpret this tracing clinically? What would you do? And just think to yourself, how would you approach this again? 51 years old palpitations. What do you think the rhythm is? What do you wanna do first? And I always break this down by saying, well, we've got the rhythm on one hand and we got the patient on the other hand. So if I showed you this rhythm, what's the first thing you wanna do? What do you wanna look at first? the rhythm or the patient? Obviously, the patient? And why is that important? Well, what if this patient is hemodynamically unstable? The reason that's important is because what if this is the rhythm and your patient is not hemodynamically stable? They're having chest pain with this rhythm, their BP is low. They're mentally confused. What are you gonna do? Does it matter at this point if this is ventricular tachycardia or a supraventricular tachycardia? And the answer is no, it doesn't matter because if the patient is unstable because of this fast rhythm, whatever it is, you gotta get him out of it as soon as you can. Now, having said this, how many of you thought that this was ventricular tachycardia? How many thought it was supraventricular tachycardia cause the cure isn't all that wide with aberrant conduction or something? And I would venture to say that neither of those answers is the best answer. Now, why do I say that? First of all, if this was ventricular tachycardia, do you have to shock the person right away. I mean, how long can you stay in ventricular tachycardia before you lose consciousness? Now, many of us kind of associate VTA and the patient's gonna become hypotensive and unconscious within seconds or a minute or so. But think to yourself, what is the longest in your medical career that you've ever seen a patient in ventricular tachycardia and stable may be aware that their heart rate is beating fast, but they have a normal BP. They're talking to you. They're not having chest pain or shortness of breath. Do you think it's minutes? Many minutes? An hour? How about a couple of days? And we had a case at a hospital just across the street from where my clinic was where I was working and basically three days, everyone was around the patient, including several cardiologists that saw the patient and they said, hey, you can't still be in ventricular tachycardia. It's three days and you're still stable. And in the literature, I kid you not, there's a patient who for weeks was in ventricular tachycardia. Now, the rate here is pretty fast. But if your rate is 150 the patient otherwise has pretty good LV function, they may stay stable for a surprisingly long period of time. I'd like to know if it was ventricular tachycardia V tac, but I might not need to necessarily shock them immediately. I might treat them with some medication. So just to keep that in mind, the good news, even if it is V tac is that the patient, if they're stable, they may stable for a period of time. Getting back to the point that I raised a moment ago. Neither of those is the best answer. In my opinion. The reason is sometimes many times, even the best rhythmologist or a rhythmologist cannot tell with 100% certainty what the rhythm is now. Sometimes I know with 100% certainty, but a lot of times it's a probability statement. So the best approach to looking at this rhythm and your colleagues who you're working with, if you're in charge of the code is to talk out loud in terms of what you have. So what is the system for talking out loud as to what the particular rhythm is? It's watch your P's Qs and the three Rs, there are five parameters that you wanna look at for every single rhythm. Once you've ensured that your patient is stable, you need to watch your PS and Qs in the three Rs. And these are the five parameters you wanna look for P waves or if you don't see any P waves, are there signs of atrial activity could be fibrillation waves or flutter waves. PS QS is the QR S complex wide and the three Rs which are, what is the rate of the rhythm, the regularity and whether if there are P waves, are they related to neighboring QR S complexes is the cure as wide. Now, what is wide? And a lot of people say wide is greater than three little boxes or 0.12 2nd. And I would submit that. It's not necessarily even that wide. It's anything more than 0.10 2nd. Each large box takes 0.2 seconds or 1/5 of a second to record half of a large box is how much it's 0.1. 0, so a QR S by my definition is wide because all it has to be is more than half of a large box. And to tell this, I look for any QR s where the beginning or the end of the QR S either begins or ends on a heavy line. Yeah, this begins right on a heavy line. And is this more than half a large box? Yes, it's more than half a large box. There's a wide QR S complex didn't look all that wide but it is wide. Why can even ventricular tachycardia sometimes be wide with a QR S of just 0.11? Well, you can have what's known as a fascicular ventricular tachycardia, the hemi fascicles, the anterior posterior hemi divisions, they're in the ventricles, you can have V tac begin from them. And sometimes those QR S complexes are not necessarily all that wide. I wanna emphasize key points about the system and then we'll apply it to today's rhythm. It does not matter in what sequence you ask yourself to be, to use three hours and I often change the sequence. I use whatever is easiest to do at the time. So I often start with P waves but not necessarily depending on it. Now, if I had a poll, I'd asked how many of you have ever used calibers. How many of you have seen your cardiologist use calipers and those cardiologists that don't use calipers, Missin. And I know because I've followed beyond them. If your patient is crashing, I don't say hold up a moment. Don't do anything. I gotta pull out my calipers. If your patient is crashing, treat the patient. But if you've got a rhythm in front of you and your patient is stable and you have a moment at your earliest convenient moment, calipers instantly make you smarter and they instantly tell you relationships that you won't know otherwise. And they end up saving time. I can use calipers within seconds. I know what's going on. Ok. Let's get back to today's rhythm. He said that better than VTA or supraventricular with a barrett conduction or something would be to describe what you've got by using the P SQS three RS PS P waves. Are they present? Do you see them? I don't see any P waves here. Now, is it possible that there may be P waves in this particular rhythm? Hint? What percentage of a 12 lead E CG are we looking at? We're looking at one single lead, you can have part of the QR S complex that lies on the baseline. QR S may look narrow in one lead, but in reality, it's really wide or you could have P waves present in some leads and not present in other leads. So I don't see P waves here. The QR S we said was why is this rhythm regular? We can look at this and say, yeah, this really looks pretty regular. We don't see any P waves. What is the rate all of you? I'm sure have different ways of figuring out the rate I like to start with the QR S that begins or ends on a heavy line here. The point of this QR S begins on this heavy line here and basically each rar intervals between one and two large boxes. Now the problem when you have a rhythm, that's this fast. If you're using the general rule, most people go by is you take 300 divided by the number of boxes in the R tar interval. Well, we're between one and two large boxes which gives us a rate between 100 15, 300. And that's a big discrepancy. And for arrhythmias, accurate, quick estimation of heart rate can be very important atrial flutter. The atria usually go close to 300. So if I have a ventricular rate of 100 90 that's too fast for 2 to 1 flutter and too slow for 1 to 1 flutter So I wanna be able to quickly estimate accurately the heart rate. And I have what's known as an every other beat or every third beat method. Let's do the every other beat. How many large boxes does it take to record? Two QR S complexes? We have one, we have two, we are getting on the heavy line just a little bit over 123 large boxes. This is half of the rate, Half of the rate is a little bit slower than 300 by three. So half of the rate is 9095. The actual rate is about 100 and 90. It really helps to know what we have is a regular wide tachycardia at about 100 90 per minute without clear sign of P waves in this one single lead that we're looking at. That's the best answer. Now, I come to this answer within seconds. So I've spent 15 minutes deriving it. But with practice, you can do this within seconds. What is your differential diagnosis? This is my differential diagnosis. This is one of my key lists of causes of a regular W CT. That's a wide complex tachycardia. When I don't see sinus P waves, there are 10 things on this list. What's number one VTA number two VTA numbers 34567 and eight VTA VTA VTA. Now, why do I do this? Think about it? But the reason that I do this is because statistically there's a literature to show if you had unselected patients presenting in a regular wide tachycardia without clear sign of sinus P waves, eight out of 10 of them before you even look at the E CG are going to be in ventricular tachycardia. So it's always BT until proven otherwise, it could be supraventricular. And a lot of times people say if there's aberrant conduction, if the fast heart rate doesn't allow enough time for there to be recovery of conduction. But what if the CRS was wide to begin with? The patient had sinus rhythm with a bundle branch clot? So this is cause number nine and then cause number 10 is something else could have WPW rhythm. You could have hyperkalemia or some other toxic cardiac arrhythmia. So the best answer for today's tracing is here. We got a patient with palpitations. We need to ensure that they are stiff. If they're not, we're going to be cardioverting them immediately. And if they are stable, the good news is even if it's V tac, how long might we have to think about what the rhythm is? You might have a couple of seconds, couple of minutes and you might have days. So I'm always ready to cardiovert with electricity at any point if the patient shows any sign of deterioration. But basically, I realize that I have a differential and it's V TVT to prove it otherwise. So I said before I even looked at the cardiogram since it's a regular wide tachycardia, 80% is gonna be VT you could get up to 90% prediction. If you just consider whether the patient is older, anybody beyond a certain age, I mean, 50 is young. Basically, it's of a certain age, fifties, sixties, seventies, not a patient in their twenties. And if the patient has underlying heart disease, then 90% of these rhythms are V tac. I have an electrophysiologist that used to say this is a telephone diagnosis. Now, can I get beyond 90% if your patient is stable, get a 12 lead. If they're unstable, we're cardioverting them, right? If they're stable, I like to know as certain as I can, but I like to get a 12 lead for two reasons. Reason. Number one, your patients in a regular way, my tachycardia, they're stable at least half of the time in my experience. By the time you get the 12 lead, your patient will be out of the rhythm and you look great. You didn't do anything. You got a 12 lead and they cardioverted. But the other reason is what to do with this patient. Long term will depend. You have to send them to the EP lab to the EP cardiologist. You wanna know what the rhythm is and being able to see 12 leads will give you an important clue. A little earlier I had asked, are there P waves and you now have 12 looks not just one. So we looked in lead two, but I'm gonna look at all of the other leads. Now, the second best lead lead two is the best lead to look for Simus P waves. The second best lead is V one because where you place V one on the chest is right over the Atria. And then I like to look in leads three A VF and A VR as other leads. And then I look at all 12 leads and I don't see P waves anywhere. Those of you that have been experienced for a while with emergency medicine, regardless of your specialty training are probably familiar with a whole bunch of rules. Some of these rules, if you're into cardiology, literature will talk about how long it takes to get to the lowest point or the highest point. And for me with a crashing patient, I can't measure millimeters. So over the years after looking at all of the literature, I've kind of evolved to what I've developed and I just call it the three simple rules. They're not perfect. They are my synthesis of what I see because you can do these three rules fast. And in my experience over the decades that I've done this, about 90% of the time they're really help. They're not 100%. Number one is there extreme axis deviation there is, it's probably VT now, what do I mean by extreme axis? I mean that if I look at lead one, which is at zero degrees. That's the horizontal lead and lead VF which is vertically looking up from the foot at 90 degrees. If one or both of these leads is all negative, that's what I call an extreme axis. Number two, look at the QR S morphology in lead V six. Now, if we think of where lead V six is, it's a left side of lead, it's over the apex, the left side of the heart. And if the rhythm is supraventricular, then there ought to be at least some active coming toward left-sided lead V six. And if lead V six is all negative, it's almost always VT. If lead V six is a tiny R wave and it's pretty much negative, then it increases the chance of VT, it's not 100%. And the third one, I love how ugly is the QR S because with aberrant conduction, most of the time, the QR S is gonna kind of look like some known conduction defect like left bundle branch block like a right bundle branch block. So maybe a right bundle one of the hemlocks. And if it's a very ugly QR S, then it's less likely to be going down the conduction system, more likely to be starting from the ventricles. Now, this is not 100% because the patient could have started with a beautiful right bundle branch block and had a couple of infarctions and cardiomyopathy and got scarring So with sinus rhythm, they may have a very ugly QR S, it's not 100%. It's nice. If you can find an old E CG to compare, you won't always have this particularly for patients crashing. But if you look at the QR S and it's very ugly, doesn't look like any known bundle branch block form, then it's more likely to be ventricular. Now we're just doing probabilities. So what I said earlier was regular wide tachycardia. It is not, I mean, there's a tendency for people to say, hey, it's VT, hey, it's uh an S VT with either a preexisting bundle branch block or Barret conduction. A better answer is the W CT and I'm not quite sure and I add a probability statement. Nothing is perfect here. I mean, we rarely 100% sure of anything except a few things we don't wanna think about. So it's all a relative probability statement. And if your patient is of a certain age and has underlying heart disease, 90% before you look at morphology, it's fatigue. Now, I'd like to get as close to 100% as I can, but 90% is pretty good odds. Here's the 12 lead. How does the 12 lead help me? Now think of those three rules. I just talked about one of them was axis. Is this an extreme axis rule number two. What about lead V six? This is a left-sided lead. It's not all negative, but it's almost all negative. So I probably moved up a bit from my 90% to 93 95%. Somewhere in that range. If I knew this patient had severe heart disease, I'm over 95%. Is this an ugly QR s? Well, not really because these are pretty straight lines. Lead V one is a little bit ugly but they're pretty much straight line. So I do not know 100% but I'm higher up than I was with 90%.