Hi, welcome to the Device Clinic Essentials for the Care Team. On behalf of MedAxiom and CV Remote Solutions, welcome, and we appreciate you taking the time to join us today. My name is Jenny Kennedy. I'm a nurse by training and part of the Care Transformation Team with MedAxiom. These are my disclosures. So as part of the first module today, we're going to be really understanding the proper technique for EKGs, as it's essential to get good tracings. We want to talk about how we can make sure we're getting the best tracings possible and how you'll review those EKGs in a systematic manner. And then really important, differentiating between what's normal, kind of cautionary, and life-threatening when you're looking at those rhythms. So as I mentioned, technique is really important, and I want to orient us to what an EKG is. So you may know this already, but it's really important that you understand what you're looking at. So an EKG is just recording the tracings of the electrical pathway that is going through the heart from the atrium to the ventricles. And it's really recording the depolarization or stimulation of the conduction to the repolarization or recovery phase. In alignment with this, without the electrical conduction, we don't have the ability for the heart to contract or pump. So this is obviously very necessary for a healthy heart. So what you're going to see is several tracings, and we're going to get into detail with that. I also want to review quickly the conduction pathway. And the impulse will start in the atrium, the right atrium, at what's called the natural pacemaker. This is the sinoatrial or the SA node. So in a healthy heart, this is where the impulse originates. It's going to further travel down to the AV node. And from here, it's going to cross into the ventricles through the bundle of His, or as it's noted here, the His bundle. At this juncture, it's going to split into the right and left bundles. And this is where it goes, takes that electrical impulse down into the ventricles, into these Purkinje fibers, and that's what stimulates the contraction in the ventricles. It's important that you understand this pathway because as we start looking at the EKG strips, the pathway can vary and cause some dysrhythmias. So within the waveform, there's different points that we're looking at. There's your P wave, which as we talked about, starts in the atrium. This is the depolarization or the stimulation of that impulse. So this is where it starts. So we're going to look at the P wave. We're going to look at the QRS complex. And that's when that impulse is traveling through the ventricle. There's also other points, the ST complex, which is ventricular repolarization or the relaxation recovery period. And the J point is also an important thing to be able to note. So one of the foundational pieces of measuring an EKG is we're looking at the time it takes for that impulse to travel. So we're really looking at that PR and QRS intervals and measuring if they're within the normal limits. Really how you do that is looking at this grid like paper. It reminds me of graphic paper. And these boxes have numerical values in terms of time related to them. So really we're looking at these boxes here on the horizontal for PR and QRS intervals. As you can see, there's a larger box that's heavily outlined. Within that box, there are smaller boxes. So one of these small boxes measures 0.04 seconds. So why that is important is when you get your tracing, you'll see a P wave and you're gonna count the amount of those boxes to maintain or to understand the time related to that PR interval. So if my P wave starts at the beginning of the box and goes over three boxes, my PR interval is 0.12 seconds. If a QRS complex covers an entire box, we know that one full box is 0.2 seconds. So these are some markings that can help you quickly count what your intervals are. In terms of lead placement, this is really important so that we're making sure to get the best possible tracings. We have six chest leads and four limb leads. So the chest leads you'll see are placed across the chest and it's important where you place them. We wanna make sure that we're not placing those electrodes, the stickers on the bony prominences. We wanna make sure that they're on the spaces or fatty places to make sure that the conduction is optimal. Now, I like to start with the chest leads. It does not really matter. You can create your own process, but it's important to know that you're using anatomical markers on the body to ensure correct placement. So I'll show you the way that I like to start and you can create your own method. But I always start on the chest, as I said, and when you feel on your sternum, there's a notch. This is where we wanna start. You'll take your finger and rub it down or take it down and you'll feel a short little notch or a bump on your sternum. This is called the angle of Lewy. And we know that at this angle of Lewy, we are at the second intercostal space. So if I go to the right, I'm already in the second intercostal space. That is the space between the ribs. So that's where we wanna make sure we're placing our electrodes. Now, you'll notice V1 is the only lead that's on the right side of the sternum. It is at the fourth intercostal space. So that means I need to go down two more intercostal spaces. I use my finger to feel the spaces between the ribs and place the electrode appropriately. Then V2 is directly across on the other side of the sternum. So again, using my fingers to feel, I can feel the space, making sure I'm not putting it on the sternum, but right in the fourth intercostal space to the left of the sternum. Now, I do not go in order here because it's a little bit easier for me to orient V4 and V6, and then I can place three and five between those. So for V4, you wanna go midclavicular. So you've got your clavicle here. You wanna go right in the middle of it. So this is your anatomical marker. You're gonna go straight down the middle to the fifth intercostal space. Now, if you have a female patient, you may need to ask her to displace her breast so that you can place that electrode underneath it. You do not wanna place it on the breast tissue because you will not get an accurate reading. Again, you can have them displace it and feel for that intercostal space with your fingers. From there, you're gonna place V6. This one is in the middle of your lateral, your side on the left. So midaxillary, you're gonna come to the middle of the armpit and come down again to that fifth intercostal space. So you can align it with V4 and come to the side of the body. Make sure, again, you're in that space and place six. From there, you're just going to align V3 between the second and fourth electrodes, again, ensuring you're not on the ribs, and then V5 is between four and six. So I encourage you to get comfortable with identifying those anatomical landmarks and feeling the difference between your ribs and that intercostal space for that placement. So next, we're gonna place the limb leads. You're gonna do the right and left for both. You will see there are two options or various options for where you place them. The optimal placement is going to be the image on the right where it's more at the shoulder level and the thigh level. There's more adipose tissue there, not so much bony prominence. So for conduction, those are the better places. However, if you have a patient in the office or in a setting where you cannot get to those, the wrist and the ankles are okay. Again, you just wanna try to place them in a manner where they're not on the bony prominences. A nice way to remember this is you have white on the right and white goes with black. So these are the colors that are correlated with those limb leads. And to remember your left side, you've got smoke over fire. So you've got the black lead over the red fire and then you have snow over grass. So white snow on the upper arm and grass on the lower leg. Again, this placement is so important. So you'll note we've got a 12 lead EKG but we've only placed 10 electrodes. Well, those limb leads are really important because they're actually giving us six different images at different planes, both horizontally and vertically within the heart. So when we're placing those, I want you to think about those leads as almost a little camera. They're taking a picture from their lead of the heart as they travel to the opposite side. So these top leads are actually what we call bipolar. So they're going from a negative to a positive. So you have a lead that's taking a picture from the right arm to the left. You also have one going from the right arm to the left leg. You then have one going from the left arm to the left leg. So you're seeing it creates this triangle which is actually called Eindhoven's triangle. And it's capturing the most efficient way to get all of the areas of the heart. So you can see what's going on in those specific areas. It only uses the left leg. That's because the right leg is really just used for grounding. So there's really no images, quote unquote, coming from that limb lead. The other views are what we call unilateral and polarity. So they're really coming from the center of the heart looking out. So your camera's at the center of the heart and it's taking a picture looking out. So again, you can see the correlating leads and giving you further insight into what's going on within those areas of the heart. So you're looking down at the foot, AVF for foot, AVL for left arm, AVR for right arm. So these will correlate with specific areas in coronary arteries within the heart. So as you are doing 12 lead EKG readings, you can correlate any issues to more specific targeted areas within the heart. So let's talk a little bit more about quality because the number one step is making sure we have a high quality EKG. If we don't have a high quality EKG, we can have repercussions, we can miss important things. So it all starts with placement. And to place those leads on correctly, you may need to do some skin preparation. We may need to make sure that we're doing some things before we apply those leads. We wanna minimize and eliminate any artifact, make sure that we're selecting the right location to place the leads, and then we wanna make sure we're taking precautions to reduce interference. So for skin preparation, you wanna make sure that you're placing those electrodes on skin that is clean and dry. So if you see any areas of open wounds, cuts, scrapes, dry, flaky patches, you want to avoid those. You may need to shave some of the patches. The electrodes are small, so you wouldn't need to do much, but if you have hair in the way and there's really nowhere near the proper placement, you may need to clip that. So there are tools that you can use to help with placement. So in the event someone is maybe diaphoretic or sweaty, you have some skin prep pads that can help clean that skin and make it dry. There are occasions when you may need to texturize the skin, or as I said, clip the skin. I know this says razors, we typically use clippers so that we are reducing the risk of actually cutting the skin. We don't wanna cut the skin and introduce any opportunities of infection to a patient. It's important that they're adhered to the skin so that we aren't getting artifact. An artifact is really just some non-cardiac electrical activity, and the challenge with that, as you can see, is it distorts the image. So we're not able to see the underlying cardiac electrical activity. So we wanna make sure that there's clear adhesion and adherence to the skin, so we're not getting additional disturbances within the tracing. Other things you can do are to make sure your patient is nice and relaxed, and still when you're capturing the EKG. A lot of times, especially in outpatient settings, our patients may not be able to get up on a table and lay flat. That is the ideal state, so they can be supine and relaxed. If that's not possible, it's okay. We don't wanna increase any distress, or if someone's at risk for falls, they may be sitting in a chair or a wheelchair. So you do have to do the best you can. Just try to get them in a relaxed position. We've talked about skin prep, so making sure you're prepping that skin. And again, that really promotes adhesion to the skin, so there's really no gaps or pooling on those electrodes. Also trying to maximize distance from electrical equipment, cords and outlets can be beneficial. So once you have your EKG, I really want you to get used to creating a systematic approach. So it's your individual process that you do on every EKG strip, so that you know you're capturing every component that you need to when you're reviewing the strips. So these components, I want you to think of it in four buckets, your rate, your rhythm, your block or the interval, and findings and how they relate to previous findings. So with rate, we know that normal is between 60 to 100. Anything less than 60 is called bradycardia. And it depends on the patient, because sometimes a patient may be bradycardic, say 40s or 50s, and they're just fine with that. So our athletes, people who run or do cardio, they may live in the 40s a good bit of the time and still have no symptoms. Another patient may be in the 40s and may express dizziness, shortness of breath. So bradycardia is really dependent on the patient and what they're used to. Anything over 100 is considered tachycardia. This is a result of some sort of stimulator that is causing your heart rate to go up. So this can be stimulants like nicotine, caffeine, can be stress or anxiety, can be infection or fever. So there is an underlying cause that's making the heart to beat fast. Rhythm is really gonna be regular or irregular. So that's gonna be a good indication and help you make an accurate diagnosis. So we really have the option to be sinus or not sinus. And it's really all evaluated mostly on the P wave. We also look at the blocks or intervals of those P waves and our QRSs because those will tell us about the conduction and if there's delays in that electrical impulse traveling through. Some of them are cause for concern and some are not. We'll get into that in just a little bit. And then once you have your interpretation, you really need to take a pause and see if this is something to be concerned about. Something's probably gonna be normal, not concerning something maybe, well, this is raising a little bit of an alarm bell or kind of a yellow flag, if you will, or there's gonna be a red flag that needs something that needs serious attention. What you can do is relate it or look back to other EKG rhythms, look at the patient's history and see if any of it's new. Any new findings obviously are cause for concern and you wanna escalate that quickly and based on the level of risk. All right, so let's start looking into those four different components. You really, first step, as we said, is determining the rate. Of course, on an EKG Holter monitor report, they do print those out. However, you can quickly calculate estimated heart rates in two methods. This small block method, you can see at each big block, these dark lines, you can count from QRS to QRS. So from this one, we go 300, 150, 100, 75 to 60. So this heart rate here is about 62 to probably 65 beats per minute. So this is just a quick way to estimate your heart rate. The other method is to look at your 10-second strip here. It's also on a 12-lead, the bottom strip. Over 10 seconds, you can calculate or count the number of QRS complexes, multiply that by six and that will also give you the estimated heart rate. So again, we're looking to see, is it normal, bradycardic or tachycardic? Next, we need to determine the rhythm. Is it regular versus irregular? And that's important so that we can differentiate diagnoses based on this. Something that is regular is gonna have P waves. It's gonna have a normal rate. So we're thinking normal sinus rhythm, sinus bradycardia, sinus tachycardia, things of that nature. They have regular P waves, regular QRS complexes. If it's sinus or not, so we've talked about rate. So even if it's fast or slow, it can still be sinus. It can still be regular. It's really important that we're evaluating the P wave and its relationship to QRS. And this is going to be the key to understanding or diagnosing the rhythm appropriately. So, our regular rhythms are really gonna be normal sinus rhythm, sinus brady, and sinus tachycardia. These are rhythms that originate from that SA node in the top of the right atrium and follow the normal conduction pathway. So, this top rhythm strip, I know it's not a full 10-second strip, but if we had a 10-second strip, we counted out our QRS complexes or have a rhythm of anywhere between 60 to 100, we see our regular P waves and our QRS complexes. If we calculate those intervals and they're all within normal limits, we are confident that this is a normal sinus rhythm. The one on the bottom, even again, it's not a 10-second strip, but you can tell this is a slower rhythm. I look at my P waves and my QRS complexes, they're all regular, their intervals are normal. So, this is a sinus brady. So, this is a regular rhythm. This is what we like to see, bradycardia or tachycardia, the patient's ability to tolerate it will be specific to that patient. There are some rhythms that are regular, but they're not sinus. So, an example of this is, this is atrial flutter. We don't really know if there's P waves in here, just initially looking at this, because if there are, they're hidden. These are actually flutter waves. So, again, even though it's a regular rhythm, it's atrial flutter, which means it is not sinus. So, just something to keep in mind that even if it's regular, that does not automatically mean that it's sinus. Irregular rhythms have differences in the PR waves and QRS complexes, and we'll talk about this in more detail. These are ectopic beats that release from the atria or the ventricle. So, they're also known as PACs or PVCs. PACs originate in the atria. As we've talked about, the SA node is the natural pacemaker. However, there are other areas within the atria that sometimes fire off that electrical impulse. So, a PAC can occur at any time. It can be a little bit hard to pick up on, but what you'll see is just an additional little P wave without a QRS complex. PVC is very similar. These are additional escape beats from the ventricle. These are generally a little bit easier to identify and spot, but you see this very irregular kind of wide QRS complex that is interrupting normal sinus rhythm. That is a PVC. Both of these are related to stimulants. So, things like smoking, vaping, caffeine, stress, electrolyte imbalances can also increase the risk of this. So, you may see, these are pretty common. A lot of adults do encounter or experience these. A lot will not even know they're occurring. Some may feel them as little flutters or palpitations in the chest, but these are considered irregular because they're interrupting a regular rhythm. All right, now I want to move into some rhythms that can put you on alert. These next several rhythms we're going to look at are related to blocks. The first one is pretty mild and is not really a cause for immediate concern, but it is something to watch. So, this is a first degree AV block. That simply means it's a delay in the impulse going from the atria to the ventricle. So, it takes a little bit longer for it to travel down that pathway. So, what you'll note, the main characteristic here is related to the PR interval. So, a normal PR interval is going to be less than 0.2 seconds. So, these PRs, I know it's probably hard to see on this screen, but if you calculate those little boxes from the beginning of the P to the QRS, you will find that's over 0.2. Again, just indicating it takes a little bit longer for that signal to travel. Generally, this is an asymptomatic rhythm. Patients generally don't feel anything. It's just, again, something to be alert to and monitor moving forward. We also have bundle branch blocks. So, if you remember, as the impulse travels from the atria to the ventricle, it comes into the right and left bundle branches. So, there can be a delay in that conduction there. So, what you'll find is a QRS greater than 0.12 seconds. So, that's three little boxes. And really, again, once that impulse crosses over the bundle of HISS, it can get switched and take over the other bundle branch. Again, not always a concern, but it can be. So, you wanna look back at the history and see if this is new or if it's been there and if it's worsened. So, there's the right bundle branch block. And if you look here, these are some of the chest leads. You're gonna see what is referred to as classic bunny ears that's associated with a wide QRS. So, it's really, again, slowered electrical impulse down the right bundle branch. This can lead to a higher AV block. So, again, it's something that needs to be monitored. This would be something you wanna report, especially if it's new. A left bundle branch looks a little bit different. Again, it's characterized by a wide QRS. And it's really indicative of an increased risk for some sort of structural heart disorder. So, thinking heart failure from a variety of causes. So, this is often associated with decreased heart function. So, this can be, especially if it's new, an indicator that we need to do further assessment and diagnosing on a patient. So, that would look like things like an echo or something, some more diagnostic testing. But you'll see, again, wide QRS greater than that 0.12. And again, really indicative more of a structural heart disease or potentially some coronary artery disease. Second degree heart block. So, this continues and generates usually from an extension from a first degree AV block. And there are actually two types of second degree blocks. The first one, the key characteristic is it's a progressing lengthening of the PR interval. And it's going to continue to lengthen until there's no longer a QRS following one. It's a very characteristic pattern. You'll see your PR interval here. At first glance, you're probably gonna be drawn to this pause here. And you're gonna wanna look a little bit deeper. So, you're gonna start at the beginning, calculate your PR interval. And as you can see, it's increasing in length time after time. And then all of a sudden after this last PR, there's no QRS complex. And then it will start over. So, it's that progressive lengthening and the failure of that QRS to fire dropping that complex. So, this is also known as a winky block. So, if you notice this pause here, some people like to remember it as it's winking at you. I like to remember it as long, long, longer drop. Now you have a winky box. So, this is a very characteristic trait and helpful in reminding you of what a type 1 AB block is. The other second degree or type 2 block is a Mobitz type 2. This one is a little bit different because your PR interval is fixed. It's not gonna change or lengthen like the last one. This one just sporadically or randomly drops a QRS. It's from a sudden failure in that atrial impulse to reach the ventricles. So, of the two type 2 blocks, this one is a higher threat. And this is something you wanna escalate because it can quickly progress to the third heart block or complete heart block. So, with this one, this is definitely a emergency situation. And as we move forward, most of these will be ones that are needing to be reported immediately. So, you wanna be vigilant and understanding and making sure that you know how to recognize these rhythms especially if you don't see them frequently. So, third degree heart block is known as complete heart block. It's complete dissociation between the atria and the ventricles. So, the atria is doing its own thing and the ventricle is doing its own thing. There's no working together. So, you really are gonna see just a little bit of chaos. So, the atria is probably gonna be firing, it's doing its own thing and then your ventricle is gonna be firing too. The other thing to note is these rates are generally slower. So, generally less than 40, 45 beats per minute, sometimes in the 30s. So, these patients need support, often can be a pacemaker temporary until they can get an implantable one. So, be alert for third degree heart block. Next, we're gonna move into some supraventricular arrhythmias. These ones are high. So, they're fast, high heart rates and they originate above the ventricle. So, they're taking a bit of a different pathway. All of these are going to be characterized by a rate of over a hundred at rest. Now, atrial fibrillation and atrial flutter are not always over a hundred beats per minute. So, I do wanna call that out. It can be controlled, but wanna make sure you're aware of these arrhythmias. So, PSVT is one that can be a little bit tricky to identify. You will note, looking at this, it doesn't appear that there's P waves. However, it's really hard to tell because the complexes are narrow and close together. So, we're looking at this and you really need to take a step back when you see something like this and do your standardized assessment. So, we note that there is no P wave. They're narrow complex QRSs. So, this is actually SVT. This can change or progress into a more dangerous arrhythmia. So, often this needs some intervention. So, this is something you wanna escalate. Supraventricular tachycardia is diagnosed on a few things. Again, so just thinking back to that strip, what you can do to further distinguish it from other diagnoses. So, as I said, in those rhythms, sometimes it can be hard to identify a P wave, but you do wanna check and make sure that there's no breaks in the rhythm or slowdowns that you are catching a P wave. So, looking just before and after that QRS complex will be key in identifying any P waves. You also wanna compare that to an EKG that the patient has had before. So, if they have a rhythm EKG, that can be helpful in identifying if they have a P wave or not. You also wanna look for any variations or increases or decreases in the heart rate and identify if there's something that triggered that. So, sometimes a PAC or a PVC can cause some sudden onset of that rhythm, or alternately, it can cause it to stop. So, just do some investigation around this one. It's definitely one to be escalated. So, atrial fibrillation and atrial flutter are very common. Atrial fibrillation is the most prominent and commonly reported dysrhythmia. So, it's really characterized as a kind of disorganized atrial depolarization. It's a little chaotic. So, within the atria, instead of it routinely firing from the SA node, there's different areas that the impulses are firing from. So, what you'll note is this rhythm is irregular. So, as you start your assessment, you're looking for P waves, and within these EKG strips, there's no P waves. So, that is characteristic of atrial fibrillation. So, when you don't see those P waves, that's gonna be one of your first considerations for differential diagnosis. Your rate can be rapid, but it doesn't always have to be. You may see normal heart rates, especially if they have a history of atrial fibrillation that is controlled by medications. So, just because it's within a normal range does not mean it's not atrial fibrillation. Your QRS complex is typically normal. So, when you, again, do your assessment, you start, you're gonna notice there's no P wave. It's irregular. Your atrial rate may be normal or fast. The important thing with atrial fibrillation is the high risk of stroke associated with this. If it's a normal rate, and they've been in atrial fibrillation, they should be on some sort of anticoagulant. If this is a new atrial fibrillation, that is something to escalate so that they can do further diagnosis and assessment. So, atrial flutter also has multiple impulses firing from within the atria. The difference between atrial fibrillation and atrial flutter is flutter is a regular rhythm. So, you can look at this and see your QRS complexes are normal and they're regular. You can't really tell if they're P waves because you've got all these kind of sawtooth or what we call flutter waves between the QRS complexes. These do tend to be faster rates. So, as opposed to atrial fibrillation, atrial flutter is typically above the normal heart rate of 100. So again, these flutter or sawtooth waves are pretty indicative of your flutter pattern. And generally, you will have a number of flutter waves, say three flutter waves to one QRS complex. So, you may hear it referred to as two to one, four to one, something like that, relating how many flutter waves there are to each QRS complex. These last rhythms, again, are not compatible with life if they are sustained. So, these are things you need to recognize immediately and be able to escalate or intervene. So, ventricular tachycardia is defined as a run of three or more PVCs at a heart rate greater than 100 beats per minute. This again is another occurrence of AV dissociation. So, there's really no connection between the atria and the ventricle. It's important to note that if it's more than 30 seconds, we consider that sustained. And it's not always coming from the same place within the ventricle. So, there's monomorphic or polymorphic VT. And if it's monomorphic, the waves will look similar. If it's polymorphic, the waves will have different shapes. And that's just telling you if it's coming from really one location or multiple locations within the ventricle. So, this is an example of ventricular tachycardia. At first look, it looks regular, but then you start to notice that QRS complex is really wide. You don't have a P wave here. Again, it can be hard to assess. So, you're gonna notice something's not right, obviously. And as you get more in tune to it, you'll be able to pick it up more quickly. And you start looking for P waves. They're not there. Your QRS is wide. The heart rate is fast. So, these are generally 150 and above for the heart rate. So, this is actually a monomorphic VT. So, this is coming from one location within the ventricle. Again, this is important that the patient gets treatment immediately. There's first-line medications and ACLS protocols, including we would shock a patient if they lose their pulse with this. And if a patient is in sustained VT, they will not be able to sustain a pulse. So, if the medication does not work, that would be the next step. Ventricular fibrillation is also a lethal arrhythmia. It is regular. It does have this kind of uncontrolled, kind of chaotic look. The QRS is, it kind of looks like you have a QRS at first, but there's really no actual QRS complexes. It's just a really erratic electrical activity, and it's very rapid. So, your monitor may pick up that it's saying it's hard to keep up with. So, sometimes it will go up to two and 300 beats per minute. Historically, I think most of the time we see it, you know, 150 to 200. Again, this is something that needs to be addressed. Immediately, it is a shockable rhythm. So, a CLS protocol would be implemented with this rhythm as well. The final rhythm is asystole. This is actually the lack of any electrical activity. So, there's no rhythm, rate, P-wave, or QRS. It's important that you're looking in at least two leads, so that maybe making sure that it's not a limb lead or a lead disconnection. So, you can see there are P-waves and QRS complexes, and then this may be a little P-wave, and then it goes to nothing. So, again, this is the total absence of any electrical activity within the heart. There are ACLS protocols associated with this. This is not a shockable rhythm. This is a CPR and medication rhythm to sustain life. So, again, this is something you always wanna verify into leads to ensure that it's true asystole, and of course, checking your patient. And with that, we will conclude the first module of the Device Academy. I thank you for joining today. If you have any questions, please email us at academy at medaxium.com.

EKG technique

interpretation

heart electrical pathway

lead placement

abnormal rhythms

dysrhythmias

ventricular fibrillation