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ECG Overview

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Summary

This on-demand teaching session offers a comprehensive exploration of ECG readings and abnormalities for medical professionals. Beginning with fundamental physiological understandings associated with ECG and how to effectively interpret and treat findings, this course offers a detailed and engaging learning experience. It also delves into the automaticity and conductivity of the heart and the formation of action potentials. This session promises to arm medical professionals with important knowledge, including understanding arrhythmias, ischemic heart diseases, and heart type atrophy. It also covers the usage of antiarrhythmic drugs in different scenarios. The session is designed to be interactive, welcoming questions and discussions throughout. Multiple sessions are available to ensure digestible and detailed coverage of all topics. Medical professionals looking to brush up on or broaden their ECG knowledge would greatly benefit from this session.
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Description

Please Note: As this event is open to all Medical professionals globally, you can access closed captions here

This will be interactive with lots of questions and learning.

This teaching session will take us through a comprehensive overview of the heart's electrical activity, aiding in the identification of various cardiac conditions.

You can find his previous event right here: https://app.medall.org/p/hussam-alkhalifamohamed

None of the planners for this educational activity have relevant financial relationship(s) to disclose with ineligible companies whose primary business is producing, marketing, selling, re-selling, or distributing healthcare products used by or on patients.

Dr. Alkhalifamohamed, faculty for this educational event, has no relevant financial relationship(s) with ineligible companies to disclose.

Learning objectives

1. Understand the physiology of the heart including the roles of automaticity and conductivity. 2. Learn about the conduction system of the heart, including the SA node, AV node, bundle branches and their functions. 3. Understand the principles of ECG, electrocardiography, and differentiate between electrode and lead. 4. Discover the components of action potential and how they relate to ECG findings. 5. Recognize and examine common heart abnormalities and arrhythmias through ECG readings.
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The following transcript was generated automatically from the content and has not been checked or corrected manually.

So we have a lot to cover uh for ECG and you are going through it slowly one by one. And meanwhile, anytime anyone wants to participate, to ask a question at any time during the chat ha uh through voice, just don't hesitate to jump in. OK. So today we'll start our ECG overview. Uh We'll start to talk about some physiological points and then we talk about ECG and how to treat an ECG. A new over review takes around 1 to 2 sessions, uh hopefully not more than two sessions. OK? And after we finish it, we have to talk about a normalities including arrhythmias and common abnormalities like ischemic heart diseases and heart type atrophy. And lastly, maybe we can talk about an antiarrhythmic drugs that used in to treat common arrhythmias in different scenarios. OK. So we all know that the functions of the heart are to uh contract and relax and the heart needs to do this a precise time or is precise regulation so that the heart can relax in the appropriate time and contract is the appropriate time to get block systemic circulation. And there are many alternative mechanisms that uh so take place uh and just the heart as uh compared to body needs. Um And uh for example, during exercise, the heart needs to increase the uh increase the cardiac output in order to match the metabolic demands of uh body system. And during the sleep, the heart needs to calm down to also much it uh because there is less demand on the heart and the heart do is doing this through uh a regulation of of the action potential. OK, of the action potential. And the action of the heart has two important features, which one of which is called automaticity and one called conductivity. So anyone remembers what is automaticity of the heart, auto automaticity of the house. But this automaticity not which cell or which tissue is yeah capable of self contracting, capable of self uh generation of electrical electrical potentials. This is automaticity in the normal physiological state. The automaticity is carried out by the sa node, the sa node for pacemaker of heart pacemaker of the heart. Why is that a it's physiologically able to, to control the automaticity of the heart? Although it's not the only cardiac cells that are that is able to, to carry the automaticity approximately every, every part of the heart can generate can generate uh electrical potentials. What is, why is it uh it's in that carries its function normally. Why not have any cardiac muscle or not? Why is this, you know, contro controlling the automaticity? Nope no. Why the rule is that uh the fastest is the one that carries automaticity, the physiological status, you know, is the fastest one. Ok. Has the rabbit has the highest strength, has the highest strength. And but in so as we, as we will see in some situations, uh in some situations, uh other cells can overcome this uh electrical potential of this anode and carries automaticity. Yes. And the other feature is the conductivity. So what is the conductivity? Zetti? Yeah. Yes. As you know is actually he's a pacemaker. What is the conductivity, its ability to propagate or conduct the action potential to different parts of the cardiac of the of the heart, the conductivity. As you will see many, many, many problems the of the issues of the ecg arise as from problem of automaticity and or conductivity and or conductivity. OK. Can anyone tell me about the components of the action potential components? Just great touch. Comparative action potential and non pacemaker cells. Yeah. OK. Depolarization. And what causes the depolarization? So the influx uh-huh after that after the depo. Mhm. So the is depolarized. Yeah. The rep and what comes next? Yes, repolarization, refractory period. Uh We're gonna see when we talk about arr was refractory period. OK. So we have depolarization as we will see in a minute initial depolarization Z A characteristic, a characteristic phase of potential of cardiac muscles. A characteristic is not found in other cells. The plateau phase, the plateau phase. And then after that comes the repolarization and then prising membrane potential, I will see you in a minute. OK. And the conduction of this electrical impulses to different parts of the heart usually generate contraction of the heart contraction, which is called uh you contraction relaxation, which cause it is called electromechanical coupling, electromechanical coupling. That is a mechanical action is is uh following the electrical action of the heart electromechanical coupling coupling. Very important. And if after every inbox conductions, there should be some mechanical action from the heart. OK. So this is when you see here a this is the resting heart muscle, resting heart muscle is is polarized. That's why it's called depolarization and repolarization. Because resting heart cell is depolarized, it's negative from inside and positive from outside. Since during the depolarization that is stimulated cell since the sodium influx generates more positive, more positive uh uh positive current inside the cell. OK. Beside the cell. And then see here is a deep depolarized cell. It's positive inside and negative outside opposite to the resting state. And then the the cell started to repolarise again. So it started to re to repolarise again. OK. Hello, everyone comes now. So this is in quickly, we have the resting muscle on negative, almost negative 90. Then de depolarization phase zero, sodium is carried out by sodium in flux. It brings the heart uh cell to positive to a positive uh potential. Then there is initialization initialization is mostly due to closure of sodium panels. And with some potassium leak out of the cell, there's a plateau phase. The plateau very important is carried out by calcium influx, calcium influx which mediates calcium, uh calcium calcium influx. OK. And this leads to contraction, contracture and then comes repolarization. This phase three pre polarization with potassium influx and the sodium potassium 80 as well carries the resting membrane potential and brings the heart to the resting state. So the heart muscle is ready to go for another depolarization for another depo OK. Phase zero. So influx, phase one sodium closure of sodium canals with some potassium efflux. Phase two calcium influx, phase three potassium efflux and phase four sodium potassium base one, just remember this for now we're gonna talk about this in more details when we talk about arrhythmias. OK. So the we said that one of the, one of the, one of the characteristics of action potential is the conductivity and this is carried out. So the conductive system who can walk us to rule the conductive system of the heart? Anyone wants to go in the state who can walk us through the conductive system of the heart? Sa knot A knot. What is between SA and ama V? Mm Can we invite people to your state? I didn't know how to do that results. OK. Yep. The impulse is uh generated from the S sinus atrial node. Sa no sinus atrial node. Z interatrial pathways from intra pathways to the Every not to the every not what, what is the function of the A knot? What is the function of the heavy ner? Yep, every not does important function that is delaying signals, delaying signals. OK. Then from this a node to inter pathways to a node then to the his his system. OK. So from near the sub superior vena cava opening is the right atrium is in a not the impulse is generated then conducted to the right atrium and then to the left atrium through in interatrial pathway. As in is the every node, every junction, the normal physiological state. This is the only pathway from atrium to from atria to ventricles, from atrial to ventricles. As you will see in some pathological conditions where we have more track, this is good result in some issues. OK. So every not delays the impulse and then send the impulses to his bundle branches. That is that we have right bundle branch and left bundle branch, right bundle branch and left bundle branch. So you as you see, they run through the interventricular septum, interventricular septum and then to the ventricle, this is important as we will see later on. OK. So from right and left branches to the ventricles and usually the action potential is generic, conducted from inside to the outside, the depo, from inside to the outside, from endocardium to the to the myocardium to the pericardium and the repolarization is going in opposite, in opposite direction, opposite direction. OK. The damage between which IW what, which part carries the fastest conductivity, fastest conductivity. Now S NF has the fastest rate and the conductivity. YP can fibers is the fastest. Which one is the slowest? Have you not? Yeah, exactly. Have you not EENT? Very good, very good. Any question regarding the these physiological points usually keep in mind these points, they are important to build up for Xanax stuff. Any questions? No question please. Right clear. So we can move on. OK, so I have a question for you. What is the EEC G? How can we define ECG? OK, good. So what is ECG? OK. Doing electrical conductivity of the heart graphic with the electrical activity of the heart? OK. For the electrical activity of the heart. OK. Snapshot it provides time, voltage recording of electrical activity can give you any stent recording of what is going on in the heart. OK, good. Very good. So it, it it it's recording of the electrical activity of the heart and is very important in diagnostic, especially in diagnosis, in diagnostic studies, in inpatient and outpatient settings, in er in uh clinics in uh for uh life-threatening conditions. That's all. No. EKG and AC are the same as far as I know. OK. So that is ECG. So what is electrocardiography? It is electrocardiography. What is electrocardiography? Mm No. What is electrocardiography? Yeah. So you remember study of ECG including the technically aspect. The basic aspect and clinical applications and so on is electrocardiography is electrocardiography. OK. So what is electrocardiograph? Electrocardiograph. What is electrocardiograph? Just missing Zawa. No, no an instrument or electrode. Which one number is it the instrument or the electrodes? Electrocardiograph is the ECG machine that we use to to record the electric activities. The A CG machine. The what is electrolyte electrodes? No, they are not the leads. There is slight difference between electrolytes and leads. So what is this electrode electrodes are the sensors that detect the electrical activity? Are the sensors that detect the electrical activity? OK. They detect the electrical activities usually at one part and the leads detect the electrical activities in two different part. Usually the difference in electrical activities. These are the leads. OK. So what is electrocardiogram? What's electrocardiogram? You have the strip or the graphic recording of the A CD or the electrical activity? This is the one, this is what we read. Usually, this is the electrocardiogram. OK. So these are general general uh is to prescribe ECG. So just not to get confused although they are used mostly interchangeably. OK. So for the electrodes, we have how many electrodes usually are used to to to measure the CJ to measure the electrical activities. How many electrodes? Now 12 are the leads? 12 are the leads. How many electrodes? Not nine, there is one always forget 10, we usually use 10 electrodes, 10 electrodes which fro from which we can have 12 fluids, 12 FS which is this in a minute. OK. We have lymphs electrodes and just electrodes from which we can have lymph leads and just leads. OK. So these are the electrodes. We have, we have six, just electrodes call it V from V one to V six. We have the three we know lymph electrolytes in addition to one, the ground electrodes on the right leg. So have the right arm, left arm, right leg, left leg, electro uh electrodes is collectively six plus four, equal 10. OK. So the right leg one, this is ground electrode. It doesn't give us any electrical activity. OK. So the actually which which, which measures actually the six electrodes and the three and the 300 electrodes. OK. So now we have nine leads. How can we get the more it actually invention? This is a scientist that invented the E CG when he invented the ce he first started with the, the Z three leads, lead one lead to lead three. So he connected the electrodes, the four limb electrodes in the right arm, left arm, right leg and left leg. OK. And then he, he, he invented the lead one that is the difference in electrons between left arm and right arm. Left arm is a positive one. A right arm is a negative one for lead one. OK. As the lead to the difference between left leg is a positive and a right arm. OK. And the three difference between left leg and left arm. So we have lead one lead to lead 33. No, no, it's, it's, it's used, it's used. So for accurate recording you should use. OK. So uh so lead one, lead, two, lead three. Look, when we talk about electrodes, we talk just about where do we put the electrode? When we talk about leads, we talk about the difference between could be between two electrodes or like the one that we put or ele another electrode that could be inside the ECG machine. As we would see in a minute, usually the leads are, is lead is the difference between two potentials. OK. Difference between two potentials. In this case for lead, one between left, between left arm, right arm lead to, between left leg and right arm lead three between left leg and left arm, lift leg and lift up. And if we draw these potentials like the, like what invention did we have? This triangle? Triaxial even triangle? OK. Are you with me up to this point? OK. OK. Good. Two. Again, we have Vicent triangle here. A OK. Lead lead, one, lead to lead three, lead, one lead to lead three. So what if we supposed that the these electrodes meet at the central point meet at the central point? OK. I will repeat no problem. Which point do you want me to repeat it from which point from uh again? We said we have six chest electrodes and four lymphs electrodes that gives us advice to, to uh to 12 leads. OK. The first three leads, we have the limb leads, lip leads that lead one lead to three difference between the electrons that we put on each limb. OK. So we have the difference between left arm. A right arm gives rise to lead one to lead one. OK. So the difference between left leg and right arm give rise to lead two has a difference between left leg and left arm give rise to lead three to lead three. OK to three. So if we just suppose that the left leg in be lies in between the left arm and right arm, then we have this triangle, we can draw this triangle. OK? For, for if we combine all the three leads, which is called in Vincent's triangle triangle. OK. So you know, we have this triangle, the lead one runs horizontally lead two and three, both run diagonally diagonally. OK? Now it's no, it's OK. Or, or they still need some mixed Lan. OK. So if, if we supposedly suppose that this lead meet at central point and we do this by moving lead one a little bit downward, lead two and three to the right and left to the right and left. So we can have this triaxial triaxial structure, OK. And B triaxial structure. So that lead one horizontally lead two and three, both run diagonally from right left or left tribe. So we can have this structure OK? For these legs, we'll see why we pull this, why we build this OK in a minute, just for now, go with me. So from in a triangle here, we are able to draw this structure on be here. OK. We are able to combine all and leads all and leads all these three leads. So now we have the three leads. We have all these electrodes that we put on the limbs. OK? For 123, just we, we move the leads downward uh or to the right or to the left. These three leads lead one lead to lead three. Like look at this is, look at it here, look at the arrows, we move lead one downward, lead two to the right lead, three to the left. OK? Now we have this structure, this tri a structure tri because it has three, a three positive, three negative. OK. So this is how we go to sleep. So lead one, lead, two, lead, three are called by B leads by baller leads because it measure the difference between two polarities, right arm, left arm and left leg, right or left leg. OK. It's called bipolar leads. Then we have it's RA L and F ra from augmented augment it. OK. Augment it here here you can find the names augmented RV. OK. What does V stand for? What does V stand for? And what does R or L or F stand for any bloody nose? A stands for Augmented V for voltage, augmented voltage. Yeah. Augmented voltage and R for right R L for left, for left, left foot, left arm and F for left foot for left foot, you said right foot is, is just the ground one. OK. We didn't count it during the measurements. So we have augmented because usually these leads are augmented one to more than 100% almost 1 50%. So, so that we can record them. OK. Every ra L and F augmented folding sometimes called vector two but augmented ting, right arm, left arm and left foot. OK. This, let's measure the difference between, between the uh between the limb and in 11 electrode that is, that is done inside the ECG. It's the ECG machine. So it is not between two different limbs. That's why we call it Unibar leads. Unibar leads or bipolar like lead 12 and three because they measure between two electrodes that is right, two lymph electrodes. OK. So we have RLF if we do the same like we did over here, we can have triax triaxial structure like what we did R is positive and negative. NL is positive and negative N and F is positive and negative and N OK with positive and negative ends. So here we have two structures. We have this one for bipolar leads and we have this one for un rates. Can we combine them to a structure? Yes, we can is a, is a bibo triaxial D is a unibar leads and then c here we have them combined. It's called hexa axial loop diagram. Hexa axial lip. Yeah. OK. Each electrode on each lead has positive and negative ends. Positive and negative ends. OK. Like like here likely the has positive end on the left arm and negative end on the right arm. That's why it trans horizontal ends. The tria structure lead two has positive end on the left leg and negative end of the right arm and so on. So each one has positive and negative end and if the wave comes toward the, the positive end, it gives what's called positive deflection as we will see. OK. Yes, exactly. So by combining the two structures, we have the Hexa diagram. Hexa diagram. OK? You see each one has positive and negative what we call polarity, what we call polarity. And each one has a special orientation inside the diagram inside the diagram. And this is very important, for example, look at least one and let every l their positive ends are close to each other one and A VR positive ends are close to each other. So that's why you'll find them have similar, similar electrical recording, similar electrical recording. OK? Also look for A R and lead two, their positive ends are opposite to each other. That's why you usually find them have have uh opposite electrical recording as we will see. So this is one of the applications of this diagram and why it is important, the other application as we will see how to figure out the cardiac axis, the cardiac axis from which this will most likely we'll talk about this next time. So now we all know how to, how this diagram is constructed and we all understand it or do I need to repeat it? Any questions? Anything unclear? Or is it clear? OK. We said when we combine, when we combine the, the two triac diagram, we have the axial diagram, just look at a look at B, we combine both of them, then we have C here, we have C OK. But all the six limb blades combined together all have polarities, positive and negative things and all have special orientation inside the diagram, special orientation. Just forget about the negative parts. Just let's focus on the positive parts. Look at positive parts of every L and lead one, lead one and lead every R. OK. Lead one and Avil, they are close to each other almost almost on the same, the same uh polarity. OK. In the same orientation. So when we, when you see, when you look at the electrical recording to the electrocardiogram, OK, you'll fa you'll find, you'll find that the electrical activities of A L1 and L almost the same are almost the same. So the depolarization that goes toward what to, to lead one gives positive and toward at the same time it goes to LDL it go, it gives positive. OK. So for example, B wave in lead one, if it's positive, that means the lead every, all it was positive, the same implies to lead 32 and F they have the same or similar orientation in SW the diagram. That's why the electrical activity is similar. OK. Zol is it, is it clear up to him? Is it, is it clear Ashok Charles? Yes, the opposite. When we look at LA R and L2, their positive ends lie, lie on opposite directions, lie in opposite directions. OK. So that's why they have uh electrical activities opposite to each other. So if there is positive B wave in lead, every other negative will lead to and so on. Ok. Ok. So that is regarding the six limb leads, then we have the chest leads, the chest leads. Anyone can tell me how do we place, place the chest leads? Where do we place this chest knees today? I talked alone. I miss you, Jorg Ashok. If anyone knows I'll do it. No, it's OK. How do we place it just leads? OK. Which intercostal is which force intercostal space, right or left? OK. Sit on left. Uh huh. OK. What about V three? OK. So what about before? And what about V six? Ok. Four. There was V five, V six. OK. So we have lead one. It's in the right for intercostal space. And I, I'm sure that everyone knows how to find the intercostal space. Right, starting from angle three and counting down. Then V two is the left fourth, intercostal space. V four is the fifth, mid clavicular line, fifth, mid clavicular line. OK. And then V three is, is in between V two and V four ZV, five anterior axillary line and V six, mid axillary line axillary line, which is the usual placement. It the same right P one is the only one to the right then from V two to V six on the left on different levels. OK. Uh The same as we used, we have B1 b2 b3 on the, on the outer chest. OK. It's the positive end of these leads. It's a positive end of these six leads or six electrodes. OK. So as we have VV one to V six here on the chest, the anterior surface are the positive ends and the posterior surface are the negative ends. It's not complicated as with the limbs. OK. It's uh so the anterior is a positive and it the posterior is the negative. The posterior is the negative. And as you see, these levels usually measure these levels are really above the, above the ventricles, above the ventricles. OK. And see that's why it's very important to if some, if someone has ischemia or infarction to the anterior part of the heart, usually the ventricles these are very important. So you can localize to his, his ischemia side, help you on localization. OK. So this is our, the chest leads and then we have the limbs. Again, if you go back, we have six chest leads, 36 chest electrodes, three limb electrodes, then we have six limb leads and six chest leads. We have three bipolar and six and nine unipolar leads. OK. So now we have 12, 12 lead E CG 12 lead. ECG. So for the limb blades, they usually measure on frontal plane, frontal plane, frontal plane mean upward, downward to the right and to the left, upward, downward and to the right and to the left. Ok. And the chest leads usually measured in horizontal plan means anterior, posterior as we just saw on the last anterior posterior and to the right and to the left. That's why E CG has 3D 3d view. It's like you record an event or a football match or uh a soccer match or every any anything we are recorded from different views using different cameras, using different cameras to get the whole view. OK, to get the whole view or it could be also described as 12 canals, but all the canals have stream, the same event, stream, the same event, but from different angles. That's why we need as many leads as we can, as many leads as we can. That's why we use 12 leads. 12 leads. So is a frontal plane and horizontal plane. So we have 3d view of the heart, electrical activity of the heart electrical activities. Ok. Is it clear? It is a 12 lead ECG only used ECG. We can only use 12. Yeah. Yes. But both are usually just another another way to measure the to lead. A CT six can be used. Three can be used, one lead can be used. It depends on, on our goal. Sometimes in in patient settings, we need to monitor patients uh electrical activity for a very long time. So we cannot use this using the 12 VCG all the time. So for example, here we have this one lead ECG with three electrodes, positive negative and ground electron positive negative and ground electrode. And it has a slightly different electrical activities than, than the usual to ECG. OK. And it depends how, where do do, where do we put them? So if we arrange this differently, we can have different literal connectivity like the one it shows here. OK. And also we have what is called ambil or um for example, if you suspect arrhythmia in a patient that doesn't occur all the time and it needs monitoring for a long time, for example, a few days, even 21 to 2 month, sometimes we use devices that patient can carry on all the time all the time and it measures electrical activity either all the time or depending on the setting of the device. So monitors as well. Monitors, am monitoring and so on. So that's why sometimes it's not, it's not uh the best practice to, to do a 12 ECG, but it's the most commonly used, it's a 12 lead ECG and the one, at least you should be familiar with for at the moment. Yes. Like Cutler, like Cutler device. Ok. So, from the 12 with ECG, we usually have waveforms, segments and intervals, waveforms, segments and intervals like this one. So what is the difference between waves or waveforms segments and, and interval? What is wave forms? Both both SS and what's the difference between these stents? Mhm Because the difference and activities. Mhm Where forms, it's what what we call the positive and negative deflections that is like in this one CB is a positive deflection that is giving positive electrical activities. QR S is another one. T is another one because it out of the wave forms. OK. We have five wave forms. B wave, QR S and T sometimes U sometimes U and CT sig is also considered a wave form by itself. OK. So that 12 forms by itself it but we are talking about an chart, we are talking about the electric activities right now, not the mechanical activities. So we're not talking about contraction relaxation. So OK, so these are the five wave forms. B wave represents atrial depolarization. Pr S represents ventricular depolarization from the start of the segment to the end of Tr U wave, this is the ventricular repolonization, it's ventricular repolarization. OK. Usually the A CG is not able to measure the atrial depo repolarization sa and A not de rep. So these are the forms. What, what is, what is the segment? How is the s which points, which points? What does AC do all the time is measuring the depolarization and repolarization if it's normal abnormal. So now we are converting this depolarization into waveform signal sign in the OK. But what is sig how do we define sig pigment is a, is a portion of the AC that is lie that lies between an end and a start of wave form an end and start of wave form. This is a segment, for example, here at the end of B wave and start of the PR S, we have a segment called BR segment, BR segment, OK. As the end of the QR S and the start of T wave, we have ST segment, ST segment. Don't, don't be confused. You have ST four and ST segment. Yeah, between the end of a wave and start of a wave. Oh OK. This is the second we have three P RST and TP. This is the end of T wave and start of the T OK. Out of here. So what is in interval? What is in T OK? Need slight modification. George interval is a portion of that contains at least one wave form contains at least one way forward. OK. Like we are inter from the start of P with until the start of the PR S. So it contains B with here QR S is all sounding terrible QR S in terrible. OK. QR S in the from the start of Q is the end of S OK. QR S, what else we have Qt Qin Terrible from the start of the turs to the end of T FT. And then last time we have RR interval that is from one QR s to the uh to another QR s also sometimes we have PP interval from one P wave to the next P wave. OK. So these are the interval. So we have waveforms, five waveform segments from an end of a wave form to the start of another waveform. And interval contains at least one wave. Four BR contain one QR S one QT one, RR and PP contains uh sorry QT more than one and RR and PP contains also more than one contain also more than one. OK. Sometimes you find T UT and sometimes you find T UTC. What is the difference between QUT and Q UTC? So let's go. So we have B QR S and TF then we have S twa OK. Sometimes you wave, then we have PR segment, ST segment and TP segment. Then you have PR interval. Pr is interval, interval, RR and P intervals. OK. Again, it's what we have FP RST NU then NST then we have PR segment, uh ST segment and TP segment TP se is there have pr interval, pr S interval, QT interval, RR and PP intervals. The interference. Is it clear? Is it clear any question? OK. So what is the difference between QT and QTC? Sometimes you find QT, sometimes you find QTC, sometimes QT QTC is a corrected QT interval, corrected QT interval. OK. Corrected QT usually is corrected according to the heart rate because with different heart rates, we have different Q and Q is measured in mainly second, that's why it's very important to correct it. Ok. It's corrected to heart rate and also it's slightly different in males and females as you will see. Ok. So uh I think you're gonna stop here for today and um yeah, next time we'll talk about how to calibrate and how to do different measurements of the A CE. And hopefully we'll be able to talk about also cardiac axis and how to treat an eg. So any question we will take, we will take the basic slowly so that we are when we come to talk about uh advanced levels, it will be very easy. Yeah, I really need people to, to go in the stage. Uh part two, part two, part two. It's just uh I will try to do it on the next couple of weeks just with, with Ramadan over here. We have condensed schedule sometimes 12 hours, sometimes more, but I'll try my best to, to be for it to be. So, uh yeah, just uh just uh follow the mid, mid all uh it all uh from Twitter on the website and it could be announced. So, yes, recorded as far as I know, all decisions are recorded, it will be soon, but just I need to make sure of my, of my schedule. Just make sure to review these, these concepts. Ok. And don't hesitate to text me uh anytime Twitter or, or uh telegram for any question. Ok, please, please. All of it provides a feedback. It's very important the feedback brought us to this topic. Ok, because I, so that many people want, uh, want to, to be, to be done on sessions. That's why I, I started to talk about to see you today. So please fill the feedback. Ok, have a good day and uh best of luck to all of you. See you next time. Bye.