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Alright. Can you guys see and hear me now? I'm just going live. I'm not sure if that's gonna make a difference. How about now? Can you guys hear me now? I wasn't talking for a bit. I was trying to sort it out, but all right, you can see the slide. Can you hear me now? Can you see me now? OK, perfect. All right. I guess we'll make a start. Uh Welcome back guys. Um We're gonna be going over ECGS and ABG. Thank you very much Paul. Um This session is gonna be a lot more um application based, right? It's not as content heavy as something like Devin. It's gonna be a lot more. I'm gonna talk to you guys about how to, you know, interpret these EC GS and ABG S, what common interpretations you want to look for and then from an exam standpoint, it really is up to you guys to practice these questions. I've got a few questions here, but it's gonna be nowhere near enough for you guys to really just get into the flow of it. So kind of watch these, watch your faculty slides and then just really just practice questions like this cos it's so the only way you guys are gonna get any better. All right. So these are the titles for today. Just a bunch of cardiovascular and respiratory stuff thinking about how we can interpret results and looking at um our findings essentially and there's an overall timeline as to what we're gonna be covering today. That being said, I'm gonna have a little brief introduction into EC GS and ABG S and what each of them signify. All right. So what is an E CG? Right? An electrocardiogram. It basically allows you to visualize the overall wave of depolarization as the heart contracts. And this is done by placing a bunch of electrodes in your body and measuring the electrical activity of the heart. All it consists of various leads which are essentially specific, these specific combinations of electrodes that record the electrical activity from a variety of different angles. All right, there are 12 in total, which is why it's called a 12 lead E CG, which is put into six in the coronal plane and six in the axial plane. You have your standard limb leads, which are attached to your limbs, you have leads which are attached to your chest and you have these augmented unipolar limb leads, which you can't actually see in real life. They're just a combination of diff different midpoints of leads kind of dissecting it perpendicularly. Again, these aren't really stuff you can get examined on it's just useful to understand them, to conceptualize what we're essentially interpreting. What these EEC G need to look at is the difference involved between two electrodes. And in doing so, they provide this graphical representation of electricity going from negative side to the positive side. And you'll see as I show you guys the ecg what each of the little parts of the lines interpret right now. This is relatively useful, especially for your clinical practical assessments at the end of the year, knowing where to place your chest leads, right? And there are six different electrodes that you need to know exactly how to place. And these are different landmarks, right? So V one on your right sternal border in the fourth intercostal space, V two, right across from that on the left sternal border in the fourth intercostal space. And I've said V three here. But the exact order is that after V two, you go to V four, right? And at V four, it's the midclavicular line on the fifth intercostal space where I'm going to fill for your intercostal spaces. And once you've placed the V four, after V two, V three is placed between V two and V four. All right. And then after the V three has been placed between those two, you have V five in the anterior axillary line at the level of V four. And then V six kind of tracing your way around to the mid axillary line around your area at the same level of V four. The L rule is useful to remember the different leads and how to know where the limb leads connect to each other. It's basically the number of the lead represents the number of LS in the connections, right? So lead one has 1 L. So it's gonna be your right arm to your left arm. Lead two with two L's is gonna be your right arm to your left leg and then lead three with three Ls is gonna be your left arm to your left leg. And the way these leads are read, um If I go back to this diagram right here, it's always gonna be from negative to positive and just like in English, it's gonna be read from left to right and top to bottom. So that's a really easy way for you guys to kind of understand how to interpret these leads and how to know which lead is being talked about if you are given an image. Now, this is something I take from the faculty slides. And I thought it would be really useful to kind of visualize what each individual part of the EC G looks like because a lot of squiggles and bumps, but sometimes it's quite overwhelming to understand what each bump kind of shows. Um the initial P wave is gonna be your sino atrial node, which is the autorhythmic monocytes and basically the depolarization of the atria. All right, the A VN which basically introduces a pause and almost like a break for the ATRIA to contract fully before the ven contract is indicated by this flat flat line. So no isoelectric activity at all, no isoelectric activity. It's gonna be the depolarization of the A VN. You have this slow signal transduction and it's called this protective feature, right. It's to make sure that there is no incomplete contraction of the atria near the end of this, right before the septal depolarization is where the bund office kind of rapidly conduct this wave of depolarization right to the apex of the ventricles. And this is insulated, the septum gets depolarized in the B along with the bundle branches and your Q wave and then your R wave, this is your ventricular depolarization. You can tell it's ventricular because it's much more of a depolarization than the atria because it's a thicker and larger muscle and it's where your peak purkinje fibers are transmitting the wave. And then at the end with your S wave, there's the late tri depolarization, right? The ventricles aren't completely depolarized at the end of the R wave. So this is the end with a negative displacement. And then once the ventricle is completely depolarized, you have a break almost like a refractory period um where the isoelectric E CG it's at zero net and no net deflection. And finally, you have your repolarisation, which is still T wave, which is where the vets become repolarise. All right. Now interpreting an E CG, you'll be doing these loads and placement and especially in an exam setting, you guys got to know exactly what to do, right? So as with any sort of imaging, so even stuff like x rays and ultrasounds, the very first thing you have to do is confirm your patient details, right? Because the last thing you want to be caught doing in a ward round is interpreting the the EC GS of an incorrect patient. So always confirm the patient's name, date of birth date if they have a hospital number. Um by date I referring to the date at which the E CG was carried out. Alright. Um I've put verified voltage and paper speed in brackets because it is one of the steps but it's not something you're required to know. But the next thing for you to do after that is calculating the heart rate. Alright. And there are different ways you can calculate the heart rate. There are two main methods that we're taught. The easiest method that I like to use is counting the number of large squares between two QR s intervals and doing 300 divided by that. Alright, so you guys might be able to see here where I put the arrows between two of the T peaks. Alright. And between these peaks, I can count just under 4.5 large squares. So I've approximated 34.4 large squares. Alright. And to work out your heart rate and BPM, you wanna do 300 divided by this number of large squares to get 68 BPM alternatively if you want a really quick way and you're just approximating you can do the number of QR S complexes and multiply that by six. Alright. So look at the entire stretch, how many have you got? Hit? 123456789, 1011, 12 QR S complexes across the whole six second kind of like or across the whole lead and you multiply this by six to get a BPM of 72. All right, a normal heart rate for the average adult is gonna be 60 to 100. Obviously, this varies with um age, athleticism will be going into that, but less than 60 you're gonna be bradycardic and more than 100 and you're gonna be tachycardic. Now, variations in um ec GS, you can have your sinus variations which are vastly benign, not really pathological. Your sinus rhythms gonna be a normal um Every P wave is followed by Curis wave and you have a regular rate and rhythm. Your sinus bradycardia is where again, regular rate and rhythm and everything, but it's just slower than usual. All right.