Cardiac Conduction System and Understanding ECG, Animation.
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- เผยแพร่เมื่อ 28 เม.ย. 2014
- The cardiac conduction system explained clearly and simply.
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Please NOTE: this video talks about PQ segment, not PR interval, and this is NOT a mistake. You may have seen more of PR interval in text books, because it is used for ECG interpretation. But you should be able to find PQ segment too. These are 2 different things. The PR interval measures from the start of P wave. So PR interval = P wave + PQ segment. To understand ECG, we intentionally use PQ segment as it represents one single event, easier to understand. The PR interval is used, however, to interpret ECG. You can see how to use PR interval to interpret ECG here (this is another one of our videos): • How to Read ECG/EKG, P...
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The cardiac conduction system consists of the following components:
- The sinoatrial node, or SA node, located in the right atrium near the entrance of the superior vena cava. This is the natural pacemaker of the heart. It initiates all heartbeat and determines heart rate. Electrical impulses from the SA node spread throughout both atria and stimulate them to contract.
- The atrioventricular node, or AV node, located on the other side of the right atrium, near the AV valve. The AV node serves as electrical gateway to the ventricles. It delays the passage of electrical impulses to the ventricles. This delay is to ensure that the atria have ejected all the blood into the ventricles before the ventricles contract.
- The AV node receives signals from the SA node and passes them onto the atrioventricular bundle - AV bundle or bundle of His.
- This bundle is then divided into right and left bundle branches which conduct the impulses toward the apex of the heart. The signals are then passed onto Purkinje (pur-KIN-jee) fibers, turning upward and spreading throughout the ventricular myocardium.
Electrical activities of the heart can be recorded in the form of electrocardiogram, ECG or EKG. An ECG is a composite recording of all the action potentials produced by the nodes and the cells of the myocardium. Each wave or segment of the ECG corresponds to a certain event of the cardiac electrical cycle.
When the atria are full of blood, the SA node fires, electrical signals spread throughout the atria and cause them to depolarize. This is represented by the P wave on the ECG. Atrial contraction , or atrial systole (SIS-toe-lee) starts about 100 mili-seconds after the P wave begins.
The P-Q segment represents the time the signals travel from the SA node to the AV node.
The QRS complex marks the firing of the AV node and represents ventricular depolarization:
- Q wave corresponds to depolarization of the interventricular septum.
- R wave is produced by depolarization of the main mass of the ventricles.
- S wave represents the last phase of ventricular depolarization at the base of the heart.
- Atrial repolarization also occurs during this time but the signal is obscured by the large QRS complex.
The S-T segment reflects the plateau in the myocardial action potential. This is when the ventricles contract and pump blood.
The T wave represents ventricular repolarization immediately before ventricular relaxation, or ventricular diastole (dy-ASS-toe-lee).
The cycle repeats itself with every heartbeat.
All images/videos by Alila Medical Media are for information purposes ONLY and are NOT intended to replace professional medical advice, diagnosis or treatment. Always seek the advice of a qualified healthcare provider with any questions you may have regarding a medical condition.
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thank you from my apex
lmao at first I was like, "what"? and than a few milliseconds later I'm like "omg, why didn't I ever think of this phrase!" :D
Indeed
Hi please subscribe me i have made alot of video
haha
🤣🤣🤣😅
Finally found a video that nicely connects ECGs with the pumping of the heart. Thanks
Exactly
And that's what we want...how and ekg and the heart are correlated
Thank you very much ❤️❤️❤️
I have a book of it.
Hey gorgeous i think you are the actress who acted in prince movie😊😊
Thank you so much. I've acquired bits and pieces throughout the unit, but haven't had a clear picture. This brought all of the pieces of the puzzle together. Thorough and informative, yet short and condensed; Just how I like it. Thanks again!
thank you from the bottom of my ... heart i guess
usergroupX lol super cool.
Do you know the bottom is technically at the top?
...from the apex of my heart :)
loooooooool
NAWLEJisPOWR I know
Sometimes I wonder why am i paying so much for my school fees when i dont get high quality lecture like this one over here hahaha
Because of certificate
This is the absolute best description of what is going on in the heart during the EKG on the INTERNET! THANK YOU!
Please NOTE: As we got this question a lot, we just want to clarify here: This video talks about PQ segment, not PR interval, and this is NOT a mistake. You may have seen more of PR interval in text books, because it is used for ECG interpretation. But you should be able to find PQ segment too. These are 2 different things. The PR interval measures from the start of P wave. So PR interval = P wave + PQ segment. To understand ECG, we intentionally use PQ segment as it represents one single event, easier to understand. The PR interval is used, however, to interpret ECG. You can see how to use PR interval to interpret ECG here (this is another one of our videos): th-cam.com/video/wPKC1X0yUQ4/w-d-xo.html Thanks for watching!
Nice
So the video should be showing the PQ segment going from before P until the beginning of Q, correct?
But that is also called the PR segment in many different sources, so it was a bit confusing! Also, wouldn't that segment determine conduction through AV node and AV bundle? The PR interval is what determines the time required for the travel of signal from the SA node to AV bundle to my understanding. Please correct me if I'm wrong.
ekg
this is pure gold for studying for my physiology class! amazing
SAME🤩🤩
@@khulemagutshwa1220 me too
glad it helped
I am a university professor and I admit TH-cam is the best professor in the world. You should not take internet for granted.
I absolutely love this concise yet detailed explanation! Thank you
This is so well explained I want to cry! You are doing an amazing job showing us that there are no difficult chapters, only poorly explained ones.
Much love from a French med student 💙
so am ı .ıam Turkish doctor.good lucky
wow, this video basically explains whole chapter about Cardiac physiology. I did not understand cardiac events in the class, but i understood here. I just have to study the notes i took while listening to your video. I appreciate you had subtitles too which made a lot easier. Very useful
Another question that we got often with this video: what is that DEPOLARIZATION and REPOLARIZATION? The answer is in our new video about cardiac action potential, here : th-cam.com/video/v7Q9BrNfIpQ/w-d-xo.html . The link is also in the "i" section of this video. This will help to understand the overall picture of how the heart works as well. Happy learning!
thank you this was so easy to follow especially having the heart animation shown as the waves go by to show how the heart pumps blood throughout. very easy to understand than my prof's notes!
It’s amazing how the ECG shows how action potential is moving across the membrane. From SA node to AV node action potential is facing (+) ^ PR interval. From AV to left Bundle Brunch( -) PR segment and negative deflection QRS complex( ventricular depolar/ atrial repolar. When the base is being depolarized (^ +), the signal continues upwards(-) etc.
2 words to describe the heart. YOUR MAJESTY!
The use of visual diagrams really helped me better understand this concept, thank you
Thank you so much! So short and simple - yet, well explained. Crazy how EKGs are such a challenge for most of us. This helps me a lot with understanding the basics before I begin my calculations & interpretations in a few minutes!
Hi gd am currently pursuing the ekg course do u got any past exam papers to share will appreciate it thanks
My 3yo has a resting heart rate of 53 from 68 when she was 2yo... she likely has progressed to 3rd degree heart block... this video has helped me to visualize and understand the function of the heart. Thank you
This is why I appreciate TH-cam. I finally understand this in under 4 minutes rather than a lecture for 5 hours and reading the textbook that has too many pages that explains this
OMG this is amazing! I wish I seen this earlier during nursing school! So much easier to understand! Thank you for this! So helpful now while studying for NCLEX
Since when do nurses read ECGs lol
Wow. Why can't everybody explain like you. Hatsoff sir. Thank you for this video.
BEST EXPLANATION EVER!! o.O! THANK YOU SO MUCH! GoodLuck for my NCLEX exam!
Thank you for keeping it simple and short as a PQ segment!
I'm 16 and these videos help me to study biology on purpose to pass school exam. The way of explanation and colorful pics are fabulous! Thank you very much, greeting from Russia 😁👋
I just wanted to say this was an excellent video. Thank You.
I liked this presentation. Well illustrated and good speaker's clarity and pace. Thank You.
Around minute 2, I'd say though, the PR or PQ segment is the time the signal is held up by the AV node before firing.
I can seriously not thank you enough for how amazing this video is. I've spent weeks looking for a good ecg video and I have now found it!! Thank you! ❤️
Thank you so much for this amazing video. It’s really get to the point. I have added your web as apart of my research sites for my nursing degree file. Again, thank you so much for what you have to offer.
If you thumbs down this video, you are special... This video went straight to the point and made the material clear.
It's university teachers that are jealous what takes them 10-15 to explain can take less that 4 and be more informative.
thanks for saying im special
Amazingly simple yet perfectly detailed. Thank you!
Thanks for the video, direct and easy explanation for medical students!
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This is the MOST SIMPLEST EXPLANATION EVERRRR !! Can't thank you enough for this 😁😁🙏
You're very welcome!
I've struggled for weeks to understand this, and now I do. Thank you so much!
Best ever in 4 min .saw lots of videos of hours and hours. But ultimately understood the concept in just 4 mins
This is the most informative, easy to follow, yet concise video I've found on this subject. Thanks for posting!
so clear and easy to understand! thank you!!
this is exactly what we want
short and easy yet covering pretty much everything
Thank you!!! After about a dozen videos, I finally understand the difference between the QRS complex and the ST segment.
thank you alila medical media for your sharing
I’ve been searching the whole internet for the last 3 week trying to find a video that introduces me to ECG and finally I can say now that I know what ECG is, well and simply explained sir.
Been reading many books but this vid has made everything crystal clear. Thanks for the vid :)
You, sir, are amazing! Thanks so much for helping me to understand this better :)
you explained what i learned in my 3 hour anatomy and physiology lecture in 3 minutes. Impressive.
18 hours worth of lecture summarized in 3 hours worth of youtube videos. The cycle continues.. Lmao
I have a test coming up and the book was confusing me, thanks for this short and easy-to-understand explanation!!
My instructor literally explained this for 2 hours and I did not get it! Watched this video once and completely understood it immediately!! Thank you!
The number of hits on this video is living proof of how bad our teachers are.
My teacher literally went over this in less than a minute and I was like uuuh... what?
I agree with you
agree lol
she just set this as homework to watch
I am doing a En course at this institute, I have to watch first aid on TH-cam because my teacher is literally reading off slides and told us to go figure it out. I am just over it and yea, it is bad that some people rather get paid to just read the slides rather help engage and actually teacher... i should have done the online option.
OMG this video help me big time in understanding the cardiac conduction! I will definitely support your channel by buying one of your merchandise.
Thank you very much. A tons is added to my knowledge. I am IT graduate and currently working on ECG data and got exactly from your tutorial what i was looking for
Thanks for sharing this video. Very helpful and way easier to understand than any other books and websites
Wow...Explained very well...Thanks
Very knowledgeable.
wow,,, I dont even speak English, but this helped me understand how my heart works D:
Thank you for this fantastic video. I have struggled with this, and you have made is the easiest thing to understand in a less than 5-minute video.
Crystal clear explanation,you saved my time !!
Perfect, thanks so much!
Nice explanation. thank you!
Wow, the clearest explanation I've ever seen!
I just wanted to learn about the humane heart as I was interested in the heart beat and this was insanely helpful! Thank you kind stranger!
My university has tried teaching me this through 3 in depth lectures.... and I never understood them. I have an exam tomorrow and
I completely understood and learnt this in 3 minutes lol
Nikko Necesario which university?
Incase anyone need this in words :)
Sinoatrial node or SA node is the natural pacemaker of the heart. It initiates all heartbeat and determines heart rate. Electrical impulses from the SA node spread throughout both atria and stimulate them to contract.
The atrioventricular ir AV node serves as electrical gateway to the ventricles. It delays the passage of electrical impulses to the ventricles. This delay is to ensure that the atria have ejected all the blood into the ventricles before the ventricles contract.
The AV node receives signals from the SA node and passes them onto the atrioventricular bundle - AV bundle or bundle of His.
This bundle is divided into right and left bundle branches which conduct the impulses toward the apex of the heart.
The signals are then passed onto Purkinje fibers, turning upward and spreading throughout the ventricular myocardium.
Electrical activities of the heart can be recorded in the form of electrocardiogram. ECG or EKG.
An ECG is a composite recording of all the action potentials produced by the nodes and the cells of the myocardium. Each wave or segment of the ECG corresponds to a certain event of the cardiac electrical cycle.
When the atria are full of blood, the SA node fires, electrical signals spread throughout the atria and cause them to depolarize. This is represented by the P wave on the ECG.
Atrial contraction, or atrial systole starts about 100 milliseconds after the P wave begins.
The P-Q segment represents the time the signals travel from the SA node to the AV node. The QRS complex marks the firing of the AV node and represents ventricular depolarization:
Q wave corresponds to depolarization of
the interventricular septum.
R wave is produced by depolarization of the main mass of the ventricles.
S wave represents the last phase of ventricular depolarization at the base of the heart.
Atrial repolarization also occurs during this time but the signal is obscured by the large QRS complex.
The S-T segment reflects the plateau in the myocardial action potential. This
is when the ventricles contract and pump blood.
The T wave represents ventricular repolarization immediately before
ventricular relaxation, or ventricular diastole. The cycle repeats itself with every heartbeat.
WOW! things got in my brain quite naturally after I saw this video and read the book. thank you so much for creating this! very grateful.
you just save my life... best video ever. Exactly what i was looking for, thank you so much sir
This is an amazing video!
Very Good ....nd...Well explanation....Nice vedio.....Easy to undrstand and...learn this process.....
Vikas
Swati Mehra wish I could say that about your comment.
SUPERB graphics and detailed explanation as per the graphic progression !! Better than most orhers I've seen ❤
you really make it easier for me to understand the conductive system of the heart. Thank u
nice video! ButI have one question:
What is the connection between re/depolarization and the graph beeing negative/positive? E.g. the Q wave is the DEpolarization of the septum and the graph becomes negative, then the R wave is also DEpolarization of the ventricles but it goes up, and then down again in the same event? I don't really get how the graph is oriented or what it relates to..
I hope someone can help me, thanks!
+1cityandcolour1 The direction of the electrical signals (be it depolarization or repolarization) determines the positive/negative values : Depolarization towards a lead produces a positive deflection, depolarization away from a lead produces a negative deflection. The reverse is true for repolarization. So the graph looks different for different leads. The graph presented here is for lead II, or III - the most popular leads - the ones that are located below the heart, roughly in the same direction of the cardiac axis. It may look completely different for another lead (avR for example). Please see our video on the 12-lead ECG for more info : th-cam.com/video/kwLbSx9BNbU/w-d-xo.html
1cityandcolour1 its mentioned in harrison ... its jst the cancelling and summation occurs ... ecg is not that defenite for each muscle
Whoa! That is a longggg question!
hey my dear.. It is too late but I just want to answer to your question all Q R S are depolarization waves but their being negative or postive is according to the direction of electrical conductivity on them if it is with the cardiac axis or not
you know that the cardiac axis is downward forward to the left.. and represents the total summation and direction of electricity in whole heart..
if the impulse is with the axis i.e downward forward to the left the recorded wave is positive ant vice versa ... q wave os negative because electricity is conducted to septum from the end of left bundle branch upward to right ie completely opposite of cardiac axis and it is very small because septum is a thin wall.. and is conducted to ventricles through rt and left bundle with cardiac axis at the same time .. finally s wave is negative becuse purkingie are directed upward to base to depolarize the base of heart against cardiac axis
and remember that the amplitude of the wave depends on the thickness of muscle depolarizing so sometimes q wave is not recorded
Mostafa Walid Hey man, thanks for you answer. In the past year since I wrote that comment I also had physio class, so now I also figured it out :D But thanks anyways, I really appreciate it! :)
I don't even know why I went to school
cause i told you so christian
Ur Mama 😂😂😂😂😂😂😂
This is funny 😂😂
Once sit alone and think about it. You will find your answer.
For a piece of paper.
Simple, short, clear... essentials, very good!
It is amazing how much i learn everyday by watching these videos
I always thought the top of the r wave was when the ventricles contracted.... I was wrong
Can you please do both the pulmonary and lymphatic systems?
We already have those, just look them up on our channel!
@@Alilamedicalmedia sounds good thanks!
Great explanation! This couldn't be better. Very well done!
This helped me passed my Arrhythmia test. Well explained!
Hi,
Can I get your permission to use this video for teaching our students please?
+Sunitha Sampath You are welcome to link to or share/embed the TH-cam video. But if you need to download it please purchase a license from our website. Thanks
Many thanks
If P = depolarization (more positive)
and T = repolarization (more negative)
Why are both depicted by a positive upward bump on the EKG?
+ElementalSkater001 repolarization works in the exact opposite manner. during depolarization positive deflection when heading towards a lead. depolarization equals positive deflection away from the lead. myocardium cells depolarized from inside out and repolarized from out side in. hope this helps. but this is all dependent on muscle mass, infarct and a list of other issues that may be going on
it is because repolarisation,it is negative charges moving from outer myocardium towards innermyocardium or simply the negative charges are moving from ventricular myocardium towards the negative lead connected to your hand so,negative charges moving towards negative lead produces positive deflection in ecg,afterall (-*-)=+.......
Best and most understandable representation of EKG tracing ive seen. Keep up the good work. God Bless
god bless people like you
Thank you. This makes my anatomy class a lot easier.
At this point, I'm wondering if our teachers themselves understand the material they present.
Maybe not, but you could tell them that you found this video very helpful.
الضاهر بس اني عربي 😿🥴😂😂👋🏻
This helps me a lot. I have presentation due monday and able to understand an ECG strip way better for my exam.
Wonderful & simplified my understanding of the marvelous heart machine ! Thank You !!
Why am i studying this im 13 and still in middle school our class is not even close to learning about this lol
that polarization repolarization needs some explaining
Imagine repolarization as the charging of the node.
When it is fully charged, it will send out it's energy as a pulse. This is called the depolarization phase.
Helmaerl Cheny Cells are polarized, meaning there is a difference in electrical potential across the cell membrane: positive charge outside, negative charge inside. That is the resting state of the cell. When a cell is depolarized - there is a change in electrical potential making the cell membrane "less polarized'. This is when the cell is electrically active and fire action potentials, in this case, it causes contraction of the cardiac muscle. The cell then returns back to the normal resting state - being "repolarized" - this is when the muscle is relaxed.
+Helmaerl Cheny As we got this question a lot, we have made a new video about action potential, depolarization/repolarization here - this is the process in neurons, but the principle of depolarization and repolarization is the same, this will help clarify further: th-cam.com/video/iBDXOt_uHTQ/w-d-xo.html
Helmaerl Cheny hahahah
I now finally understand how pqrstv wave works. The best!!!!
i swear these
Not digging Medicine , just watching this for fun
no words are enough to thank you.....i am sure i would never get it this way from my teacher ....so tanks alot
Awesome! It makes me understand ECG so well! Thank you!
thank you for this video, straight forward and easy to understand!
short and complete video ! thank you ! after the T vawe there is the U vawe = the ripolarization of the papillary muscles wich prevents valve prolapse when the pressure in the ventricle is maximal
The cardiac always scared me, but damn this video was so well done I feel absolutely enlightened. I guess I never like cardiac only because it was never explained to me very well. Thank you from the bottom of my heart for this resource.
The best video of cardiac conduction system ( believe me I’ve watched a lot )
This is the best explanation for this topic
so simple in under 4 minutes. thank you!
Extremely good explanation heartiest thanks
This is way better than the videos my teachers put up, they usually put-up Dr. Bruce Forciea's videos. His videos are narrated by a robot and there is no proper explanation such as the one you see in this video. Sometimes it is oversimplified.
Thank you! Great video! Very thorough and easy to follow !
Very good animation, explanation it will help all Medical community...