Cardiovascular | EKG's

iron engineers were going to talk about EKGs so before I get into all of these abnormal EKGs because we're gonna talk about each one of these and a little bit of detail we'll go over them in much much more detail whenever we get into pathophysiology for right now I want to take a look at just a basic EKG another thing that we'll look at in future videos is we'll go over the 12-lead system so we'll go over the three bipolar limb leads the three augmented unipolar limb leads and the six chest leads but for right now we're gonna just take a basic look at an EKG and then some common abnormalities first things first if we look at here the EKG we have three distinguishable waves right this first one right here we refer to this wave as the P wave all right so this is our P wave so P wave is this positive deflection from that isoelectric point right so we have that positive deflection then you might see this little negative deflection right there that's your Q are S wave so we have our QRS wave and then this last wave over here with this other positive deflection is the T wave now let's talk about each one of these waves what they are designed to what they specify so first off let's go over here to P wave P wave so the P wave tells us that the atria are depolarizing in other words whenever the atria so you start off with the SA node the SA node fires those impulses throughout the entire internodal pathways and Bachmann's bundle and it reaches the AV node what happens is once it reaches the AV node the atria depolarize and they can track the undergoes systole but that electrical activity that shows up on here on the EKG with this positive deflection point is designed to tell us that there is atrial D polarization and again we already know a depolarization means it means that the inside of the cell is becoming more positive it's conducting action potentials right this next one over here is the QRS wave so we have the QRS wave over here now the QRS wave is obviously this big negative positive negative deflection and this represents ventricular depolarization so it does represent ventricular depolarization and what that means is that whenever those impulses from the AV node they reach the AV node there's a point 1 second delay that we talked about in the cardiac cycle it sends those impulses down through the ventricles down the AV bundle right and left bundle branches Purkinje fibers and as it's moving around those guys it's causing the ventricles to become depolarize in other words the inside of their membranes are becoming more positive and then eventually that will trigger ventricular contraction which we talked about in the cardiac cycle so again that's been tricular depolarization another interesting thing is cells need to go through a relaxation period so they need to depolarize and then they need to repolarize so they can be excited again so if you notice we didn't mention here where's atrial repolarization well it's your repolarization is hidden or masked within this QRS complex so we can technically say it within the QRS wave there is a hidden or masked atrial repolarization occurring so let's write that down here atrial repolarization is occurring there's atrial repolarization and ventricular depolarization occurring within this QRS wave and again you can't see the atrial repolarization because it's masked by this positive negative deflection points within the QRS wave next one is going to be the T wave and the T wave is what signifies the ventricular the ventricles repolarizing so after they've all contracted but after going through the refractory period so that they can actually get all the oxygen to the tissues because that's when the coronary circulation is filling and once it starts doing that has to repolarize and then get ready to be excited again so we say the T wave is representing ventricular repolarization okay so now that we have a basic concept or an understanding of what all doesn't just basic EKG tells us now we can take a look at some of these common abnormalities within the ECGs like I said we're gonna get into these in more detail when we get into pathophysiology just a brief overview of some of these so if you look here we have a normal P wave on this one we have a normal QRS complex but if you notice here compare this with this normal T wave this R right here we call this part right here the ST segment from this part here to this part here it's the ST segment and then we refer to this from the beginning of the P wave to that Q that's our PR interval right so here's our ST segment I'll write that there ST segment and then this right here is our P R interval right PR interval looks good but the ST segment looks like it's elevated so we call this an ST segment elevation sometimes in hospitals you'll hear referred to as a STEMI all right an STEMI is short for saying ST segment elevation myocardial infarction and so you would see if someone has a ST segment elevation and most likely is indicative of some type of myocardial infarction or a heart attack but obviously you could do other diagnostic testing to prove that all right that's one of those differential diagnoses then over here you'll notice in this one that there's a normal P wave normal QRS complex but then the T waves flipped it's inverted so now there is a t-wave inversion so this one is a t-wave inversion now T wave inversions are indicative there is ST segment depression I didn't want to talk about that again we'll talk about in more detail later but just simply T wave inversions are usually indicative of ischemia so they're usually indicative of ischemia and ischemia just means that there is a decreased oxygen supply or lack of a decrease lack of blood flow to the myocardial tissue and it's going to cause this and negative deflection this again that's a t-wave inversion let's go over here this one so now we look at this guy what do we notice we know it's a normal P wave all right then we notice the PR interval here QRS complex then we got our T wave then we go over to our P wave and then we notice that this there's our PR interval QRS complex T wave now the only way we'll be able to like determine why this is abnormal is if you actually look at the ECG paper if you look at the ECG paper there's little blocks that identifies the amount of time it takes if the PR interval normally the PR interval is about 160 to 200 milliseconds if it's greater than that then there's a prolong PR interval what happens in this one and I'd obviously I need an ECG paper to see that but there's actually going to be a prolonged PR interval right here but it's consistent it's not it's not varying it's a consistent prolonged PR interval so let's say it's greater than 200 so it's 220 milliseconds here and then over here this PR interval even though it's not looking like it it is two hundred and twenty milliseconds also if someone has consistent PR prolongation PR interval prolongations but it's not progressively getting longer this is described to be what's called a first degree heart block which are physiologically normal okay there's nothing really designed to be you know this is not life-threatening it's very common obviously stress anxiety certain things can actually trigger this to happen but it's not a life-threatening there's no need for a pacemaker or anything like that all right next one if you look over here we notice the PR interval is long and then it actually locally was getting a little longer and then eventually over here you notice there goes T wave P wave oh no QRS wave what happened there so if we look again what was I saying let's say that this PR interval let's say it's 220 milliseconds then we come over here in this PR interval let's say it's 240 milliseconds so again we have our T wave here then we got our P wave but look guys no QRS complex and then we go back to a P wave this is referred to as a second-degree heart block and you can actually say this is called mobitz one or Lincoln block and how do you describe that you say that the PR interval is getting progressively longer and then you drop a QRS interval all right QRS wave sorry all right so that is one thing to remember for a second-degree heart block mobitz one now second-degree heart block mobitz one is more common within some type of inference oh there's a block we're usually within the AV node we'll go into more detail that in paths office but for right now just remember time a cause of it is usually an infra nodal block now second-degree mobitz one can progress into mobitz - and again mobitz 1 isn't super life-threatening but it's obviously you know it's a partial heart block if we go over here this is a little bit more you know dangerous you got to be careful with these ones this is a second-degree heart block mobitz - now a second-degree heart block mobitz to the PR interval is normal so it's normal PR interval it's not it's not fluctuating obviously I didn't show it perfectly there but the PR interval is normal that's not changing it's not going from 220 to 240 it's a normal PR interval about what you notice is here's your P wave PR interval QRS wave T wave and then that's our P wave but then if you notice what happened we dropped our QRS complex and then we go back to a PUA then we might have a QRS complex so it's kind of like grouping them and what it might look these are kind of sometimes hard to differentiate a little bit but with this one the third-degree heart block which I'll talk about it does have a varying PR interval whereas within the second-degree heart block mobitz to the PR interval is usually normal it's not changing it's not fluctuating but some of the p-waves don't make it through it doesn't get through the AV node it doesn't go down to the ventricles so the ventricles don't contract that is important to remember the P waves are going but they're not making it through the AV node they're not getting into the ventricles and the ventricles are contracting so this is called second-degree heart block mobitz - okay and just remember normal PR interval but it drops the QRS complex in there because some of the P waves don't get through and again second-degree heart block s-- some of the symptoms that you can see within these people are some syncopes and dizziness and stuff like that - okay all right let's go on to the next one this is a third-degree heart block and the third-degree heart block I've already kind of given you a little bit of information on that we already know that they're going to have sometimes you're gonna have this again so P wave QRS complex so again p q r s t wave p wave and then you go back to a P wave and then we got QRS complex and there we go T wave P wave P wave again this one is completely the worst one this is a this is a complete heart block as you would describe it so third-degree heart blocks are very very life-threatening very dangerous you're gonna need to give them a most likely an artificial pacemaker actually definitely need an artificial pacemaker but here's what's different from the second-degree heart block if the ventricles and the atria beat on their own rate so none of the impulses within the mobitz to some of the impulses from the atria actually get down to the ventricles within third degree heart block none of the impulses get through the AV node and down to the ventricles the ventricles action develop their own beating rate and the atria beat at their own rate so because of that there is no connection if you will between the atria and the ventricle functioning as well anymore okay this is a third-degree heart block so the P and the QRS wave are not agreeing correctly and they're beating at their own rate alright so that's the third guard block hi guys so now we're gonna come down to my personal favorite and this is gonna be an EKG that is indicative of what's called wolff-parkinson-white syndrome so I'm just going to put W P W syndrome okay so again this is called wolff-parkinson-white syndrome it's a congenital condition in which the individuals have an irregular accessory pathway and that accessory pathway is called the bundle of Kent and it's actually bi-directional so impulses can go through it down and tear great and it can go up through a retrograde which can create what's called reentry and it can lead to super ventricular tachycardia which is can be symptomatic and asymptomatic and stuff like that usually the way to treat this as they sometimes you can do what's called radiofrequency catheter ablation where they hit this bundle of Kent with radio frequency waves creating scar tissue so that doesn't conduct the electrical potentials through it anyway let's come back here and let's look here we can see here and this one they don't really have a distinguishable P wave so they don't have a distinguishable P wave it actually kind of just goes straight up it looks coming up straight up right there that's actually a distinct wave this one we're having to draw in blue that's called a delta wave and again over here you'll see this one this is called a delta wave so again this is a delta wave here and this is a delta wave here and again this is usually indicative of someone who has wolff-parkinson-white syndrome so that's one of the big things to look for for this there's obviously more and we'll talk about in great detail and pathophysiology let's come over here and let's look at some more EKGs so we look here you're gonna see this one and right away you see the sawtooth like structures these are supposed to be a P wave by the way we don't call them P waves we actually call them F waves so this is a F wave all these are F waves all right that's an F wave and these sawtooth waves indicate that there are some P waves they're just kind of like doing through this that they're going through this reentry and then eventually some of those re entries will hit the AV node and then send the action potentials down to the ventricles and then cause the ventricles to depolarize and then again you'll have your T wave and then you might have some more again reentry circuits and then eventually some of those circuits will hit the AV node and send action potentials down atrial flutter is this condition again this is called atrial flutter it's not life-threatening but it can progress and become very serious usually atrial flutter is caused by could be due to myocardial infarctions or thyrotoxicosis like elevated t3 and t4 could be due to mitral valve prolapse is a whole bunch of reasons that we will talk about in the future but atrial flutter obviously is not completely serious but it can progress and sometimes it can progress into this one below it which is called atrial fibrillation and again you'll notice the nature of fibrillation you have these like don't even really see a P wave then it doesn't there's not distinct P waves it's just kind of like this little squiggly almost around baseline activity to where there's no P waves present it's just this kind of like irregular rhythm here and that's one of the big things to notice here they're not F well they're actually they do have names but it's here's the biggest thing they're F waves but they're little F so this is little F waves little F ways so they're both F waves except this one up here natura flutters capital F waves are these are lowercase F waves so these lower case F waves are indicative of atrial fibrillation okay a-fib you got to be careful with obviously you might have to these could be due to metabolic syndrome again thyrotoxicosis and my obesity it can go on and on and on and sometimes you might have to deal with this depending upon the condition again you might have to do radiofrequency catheter ablation you might have to do cardioversion whatever it might be we'll get into more detail on that in the future so again these are F waves but remember they're lower case F waves and this is this condition is called atrial fibrillation another danger with atrial fibrillation I just wanted to mention really briefly is that they don't really have functional contractions and so the blood pools up a lot inside of the atria and if there's stagnant flow according to virtue of triad when there's a stasis of blood flow there can be an increased chance of forming thrombi and so sometimes these can form a little vegetations on the valves a mitral valve and the tricuspid valve and get dislodged and go and cause an embolism like a pulmonary or cerebral embolism and again we'll talk about these in more detail later next one right here you're going to notice something weird and this is kind of more common in individuals who are using drugs like drug overdoses you'll notice that the P wave changes it takes on different morphological structures at least three so right here it looks like it's kind of triangular shaped over here it looks kind of like normal and over here it kind of looks like a little squiggled right whenever you notice three different morphological p-waves in sequence it's referred to it's what's called a wandering atrial pacemaker okay and again you'll notice that it's more common to like drug overdoses but you'll notice that there's obviously three distinguishable or morphological P waves okay it's a wandering angel price maker over here this is obviously common to someone who uses nicotine or so you know they drink a lot of caffeine or certain drugs and stuff like that what can happen is they can have this little ectopic focus where they could trigger a premature ventricular contraction so they might develop some irritable foci within the ventricles and it might contract before the P wave actually sends the impulses out so you'll notice here we go P wave right so we have a P wave then we got our QRS wave then we have our T wave but we don't see the P wave it kind of goes and actually bypasses the P wave because of a premature ventricular ectopic focus and it triggers a premature ventricular contraction so it's indicative of this part right here okay so this is indicative of PVCs or premature ventricular contraction okay and obviously this can be due to caffeine it could be due to possibly some type of nicotine it could be due to exercise a lot of common causes of this last one all right this guy's not having a good day this is a really really bad one this is life-threatening and it's actually called torsades de pointes torsades de pointes so torsades de pointes I think they even call it de Ponce it just refers to twisting of the points around the isoelectric line this one's really really life-threatening obviously you're going to need to treat this it's a medical emergency but with torsades de pointes it's usually referred to as a prolonged QT syndrome and the most common causes of prolonged QT syndromes are actually metabolic reason so in other words more specifically if someone has low magnesium levels within the blood or if they have hypokalemia or hypomagnesemia those are common causes and even medications can lead to those so this is a really really bad one obviously this needs medical attention immediately so this kind of gives us just a brief overview we'll get into a lot of these in more detail in the future but for right now that gives us everything we need to know about EKGs

Channel: Ninja Nerd Lectures

Views: 779,469

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Keywords: EKG's, cardiovascular, electrocardiogram

Id: 791ZsLSmCjo

Length: 20min 36sec (1236 seconds)

Published: Wed Mar 08 2017