Get My Best Tips For Passing Biology

Sign up for my newsletter and get my Free Guide!

048 How to Read an Electrocardiogram (ECG/EKG)

Have you seen an ECG reading? What do those lines mean? How does it measure heart activity? Watch and learn as Leslie once again teaches us about this topic. Enjoy!

Transcript of Today’s Episode

Hello and welcome to another episode of Interactive-Biology TV where we’re making Biology fun. My name is Leslie Samuel and in this episode, Episode 48, I’m going to show you how to read an electrocardiogram. For short, it’s called ECG or EKG.

So, let’s get right into it.

First, I want to answer the question, what is an electrocardiogram? An electrocardiogram is a test that records the electrical activity of the heart. We looked at how the  SA node starts the signal and we looked at how that signal spreads to the rest of the heart. You can always go back to Episode 46 for more details on how that works.

The ECG is used to test for irregularities in how the heart functions. You’ve probably either seen this first hand in a hospital or on TV. You can look at the electrocardiogram and it will tell you if the heart is working the way it should. The way this is conducted is by placing skin electrodes on different parts of the body.

These electrodes are able to detect the electrical activity of the heart. When you look at the electrocardiogram, it looks kind of like this {Leslie shows an animation of an electrocardiogram} and you’ve probably seen this.

Normally when you see this, there’s a beep associated with it. There’s no beep in this animation but, you get the point. What we’re going to do is we’re going to look at this and we’re going to look at each component of the electrocardiogram. Let’s look at it right now.

We’re looking at an electrocardiogram and you can see that we have a number of things. We have this peak over here. We’re going to call this the P wave, this peak right here. And then, we have this section that we’re going to call the QRS complex. Then, we have the T wave and sometimes we get this U wave. We’re going to talk about what these different waves show. The P wave. We’ve looked at how the SA node generates the signal and then that signal spreads to the muscle cells in the atria.

What this P wave shows us is the depolarization of the atria. Okay, so, when the atria depolarizes, we see this peak. We have the QRS complex, you probably guessed it by now but, this shows the depolarization of the ventricles. That is what is represented by the QRS complex. Then, we have the T-wave which comes after the QRS complex and this shows the repolarization of the ventricles.

Now, you’re probably wondering why the signals that come from the ventricles are significantly larger than this little signal that comes from the atria. But, if you look at the heart, you’ll see that the atria is significantly smaller than the ventricles. So, when the cells in the ventricles depolarize, that’s going to have a much greater effect on the EKG or the ECG because you have more cells depolarizing so you can get a stronger signal.

And then of course, you get the repolarization. The U wave is one that you don’t always see. It’s sometimes hard to see and in most cases, you don’t really see it. But, in some cases, you do see it. In some cases it can tell you something about when things are going wrong with the heart. We’re not going to go into all those details but, I included it here because it was shown in this pictures that I found and because it does show up sometimes.

Some people think it’s the repolarization of the Purkinje fibers. And it’s also thought to be the repolarization of some other specialized muscle cells. But, we’re not going to go into that. The main things are the P wave, the QRS complex and the T wave. The P wave being the depolarization of the atria; the QRS complex being the depolarization of the ventricles and; the T wave being the repolarization of the ventricles.

If you ever need a refresher on what the terms depolarization and repolarization mean, you can always go back and to Episodes 9 and 10 and that will give you more details. Well, that’s all for this video.

As usual, I’d like to invite you to check out the website at Interactive-Biology.com for more Biology videos and other resources to help make Biology fun. This is Leslie Samuel. That’s it for this video and I’ll see you on the next one.

The following two tabs change content below.
Leslie Samuel is the creator of Interactive Biology. His mission is to use this site to Make Biology fun for people all over the world.

Tags: , , , , , , , ,


Leave An AWESOME Comment

215 Responses to “048 How to Read an Electrocardiogram (ECG/EKG)”

  1. Nikhil N T June 14, 2011 at 4:21 am #

    Sir,
    The information in the video,although very useful seemed to be insufficient..SO, I would request you to make another video regarding abnormailities in each of the EKG waves..I would be thankful If you would give information about the same
    Yours truly
    Nikhil N T

  2. Nikhil N T June 14, 2011 at 4:26 am #

    Sir,
    The information in this video was very useful. But, I wanted a bit more details ..If you would provide information about the abnormalities in each of these waves,it would be very helpful.
    Yours truly
    Nikhil N T

    • Lrsamuel June 14, 2011 at 7:23 am #

      There’s always more information that can be added. However, there’s only so much that 1 person can cover. I try to give as much detail as I have. You can always do your own studies by reading textbooks that go into the level of detail you are trying to get.

      • lisa January 26, 2012 at 10:28 pm #

        where is more information on reading EKG’S AND INVERTED P WAVES AND inverted T waves.. Also some additional info to focus on mi detections and the contrast to people with pacemakers abd defibs ekg readings ..

        so far I am enjoying your videos ..

        • Lrsamuel January 26, 2012 at 10:55 pm #

          I don’t have all that info here. There’s only so much I can do. There’s ALWAYS more that can be covered.

          Glad you are enjoying the videos though.

  3. maihot June 20, 2011 at 11:43 pm #

    Thank you so much for these videos.

  4. InteractiveBiology June 21, 2011 at 4:44 pm #

    @maihot You are very much welcome!

  5. yassomatto July 28, 2011 at 2:51 am #

    thank you very much

  6. InteractiveBiology July 28, 2011 at 8:13 am #

    @yassomatto You are very much welcome :)

  7. rotorway133 August 10, 2011 at 2:19 pm #

    hey thanks for the video. I just had a ECG for the Canadian Army and the results says : ALMOST NORMAL. After viewing your video i came to the conclusion that….nah..all seems to check out OK…..with my untrained eyes :) Awaiting the final results

  8. InteractiveBiology August 11, 2011 at 6:26 pm #

    @rotorway133 I wouldn’t use my video for self-diagnosis ;) but I hope that all goes well with the results.

    • Essence February 3, 2012 at 7:40 pm #

      A pleasingly ratnaiol answer. Good to hear from you.

  9. MedAsstVera September 12, 2011 at 5:02 am #

    Excellent video!! Thanks for sharing. :)

  10. MedAsstVera September 12, 2011 at 5:02 am #

    Excellent video!! Thanks for sharing. :)

  11. InteractiveBiology September 12, 2011 at 12:05 pm #

    @MedAsstVera You are very much welcome :)

  12. asdf15 September 17, 2011 at 9:29 pm #

    Awesome video, it’s explained really well but I just wondering when the atria repolarise, does it have a peak or is it too insignificant to see?

    • Lrsamuel September 23, 2011 at 8:42 am #

      All questions are answered in the Interactive Biology community forums from now on. This is to make it as efficient as possible as we have multiple people over there to help answer questions.

      All the best

  13. missgomes18 October 15, 2011 at 10:15 am #

    what abt atrial repolarisation?

  14. InteractiveBiology October 15, 2011 at 8:40 pm #

    @missgomes18 All questions are answered in the Interactive Biology community forums from now on. Go to the website in the description and then visit the community. This is to make it as efficient as possible as we have multiple people over there to help answer questions.

    All the best

  15. cocovuitton October 18, 2011 at 9:41 am #

    @missgomes18 Atrial repolarisations are so small that they get masked on the ECG by the depolarisation of the ventricles (i.e. QRS complex).

  16. chas21969 October 22, 2011 at 1:04 am #

    this is awesome

  17. InteractiveBiology October 22, 2011 at 9:41 pm #

    @chas21969 Thank You!

  18. jaaz1802 October 23, 2011 at 9:53 am #

    i m a army doc
    n i find it vry helpful as i m on a isolated place
    thnxs

  19. InteractiveBiology October 24, 2011 at 9:16 am #

    @jaaz1802 Glad to know the videos can help you from so far away. Thanks for the work You’re doing. It makes a difference!

  20. genius4themostpart October 31, 2011 at 5:35 pm #

    why is the T wave “positive”? I understand, and it makes sense that the depolarization in the atriums and the ventricles have that effect on the EKG but not why the T wave is positive.
    Thank you for great videos, I just found your channel and i love it!

  21. genius4themostpart October 31, 2011 at 5:35 pm #

    why is the T wave “positive”? I understand, and it makes sense that the depolarization in the atriums and the ventricles have that effect on the EKG but not why the T wave is positive.
    Thank you for great videos, I just found your channel and i love it!

  22. hannasspawnofsatan November 13, 2011 at 1:20 pm #

    This is fantastic!!! I am learning so much

  23. hannasspawnofsatan November 13, 2011 at 1:20 pm #

    This is fantastic!!! I am learning so much

  24. InteractiveBiology November 14, 2011 at 9:46 am #

    Glad you found some value in it. You can check our website for more. Do stay tuned because we’re planning to upload new Biology videos very soon!

  25. InteractiveBiology November 14, 2011 at 9:46 am #

    @hannasspawnofsatan Glad you found some value in it. You can check our website for more. Do stay tuned because we’re planning to upload new Biology videos very soon!

  26. VidUploDer November 17, 2011 at 5:55 pm #

    thanks this helped

  27. VidUploDer November 17, 2011 at 5:55 pm #

    thanks this helped

  28. InteractiveBiology November 17, 2011 at 9:47 pm #

    @VidUploDer You’re welcome! Stay tuned for more Biology videos coming very soon!

  29. InteractiveBiology November 17, 2011 at 9:47 pm #

    You’re welcome! Stay tuned for more Biology videos coming very soon!

  30. akshalabi November 30, 2011 at 6:13 am #

    thank you … i have been having problems with ECG but now i get it perfectly ..thanks to you

  31. InteractiveBiology December 1, 2011 at 5:02 am #

    @akshalabi You’re welcome. Glad to know this helped. Stay tuned! We have more Biology videos coming very soon…

  32. InteractiveBiology December 1, 2011 at 5:02 am #

    You’re welcome. Glad to know this helped. Stay tuned! We have more Biology videos coming very soon…

  33. biomed29 December 10, 2011 at 4:15 pm #

    Excellent :-)

  34. biomed29 December 10, 2011 at 4:15 pm #

    Excellent :-)

  35. InteractiveBiology December 11, 2011 at 1:15 am #

    @biomed29 Thank you! Please stay tuned for more Biology videos coming soon!

  36. InteractiveBiology December 11, 2011 at 1:15 am #

    Thank you! Please stay tuned for more Biology videos coming soon!

  37. DiyaBabyee December 27, 2011 at 10:35 am #

    I don’t understand what depolarization and repolarization is?

  38. Abdulaziz Ameen December 27, 2011 at 3:43 pm #

    please your opinion about: “It mean’s a lot for me”
    youtube.com/watch?feature=player_embedded&v=TKAL0YSDHIs On
    prof.tnt@gmail.com

  39. abdulaziz068 December 27, 2011 at 3:43 pm #

    please your opinion about:

    “It mean’s a lot for me”

    youtube.com/watch?feature=player_embedded&v=TKAL0YSDHIs

    On

    prof.tnt@gmail.com

  40. Olid2010 January 11, 2012 at 3:11 pm #

    thank you until now i didnt know about the u wave this helped a lot

  41. ojay12341234 January 13, 2012 at 1:40 pm #

    @DiyaBabyee Interactive biology made videos about depolarization and repolarization, check them out.. ther’re pretty good
    There is also a video about action potential it will help as well

  42. ojay12341234 January 13, 2012 at 1:40 pm #

    Interactive biology made videos about depolarization and repolarization, check them out.. ther’re pretty good
    There is also a video about action potential it will help as well

  43. XLordPikachuX January 21, 2012 at 3:47 pm #

    this helped so much thank you

  44. evilmask972 January 27, 2012 at 3:34 pm #

    Great video! You just didn’t explain that the QRS complex mask the repolarisation of the atrium (we can see on the edge of the QRS complex that the curve goes down a little) Thanks a lot for your videos anyway! It helped me a lot! :)

  45. evilmask972 January 27, 2012 at 3:34 pm #

    Great video! You just didn’t explain that the QRS complex mask the repolarisation of the atrium (we can see on the edge of the QRS complex that the curve goes down a little) Thanks a lot for your videos anyway! It helped me a lot! :)

  46. wizardzwish January 28, 2012 at 7:27 pm #

    so what part the atrium and ventricles contract and relaxed during depo and repo?

  47. xxTaKe2xx January 29, 2012 at 8:18 am #

    You don’t see the repolarization of the atria because it is overshadowed by the depolarization of the ventricles.

  48. Nomindnotrouble February 3, 2012 at 2:55 pm #

    Thank you.

  49. Nomindnotrouble February 3, 2012 at 2:55 pm #

    Thank you.

  50. Beardfascade February 4, 2012 at 3:28 pm #

    Thank you, this has been very helpful.

  51. Beardfascade February 4, 2012 at 3:28 pm #

    Thank you, this has been very helpful.

  52. bizarre193 February 9, 2012 at 6:57 pm #

    ahaha I’m an ECG TECH and looool it helps lol :D

  53. Truthbearer1 February 13, 2012 at 10:21 pm #

    You sound Trini….good explanation! Thanks so much :)

  54. OJASVIVYAS February 18, 2012 at 1:08 pm #

    thank you so much…sir your video was a grt help..i m student of first year medicine..this was indeed superub..plzz continue the good work..looking forward to see more videos frm you

  55. OJASVIVYAS February 18, 2012 at 1:08 pm #

    thank you so much…sir your video was a grt help..i m student of first year medicine..this was indeed superub..plzz continue the good work..looking forward to see more videos frm you

  56. OJASVIVYAS February 18, 2012 at 6:08 pm #

    thank you so much…sir your video was a grt help..i m student of first year medicine..this was indeed superub..plzz continue the good work..looking forward to see more videos frm you

  57. dpsicose February 27, 2012 at 11:43 pm #

    Can anyone explain why P,R,T have a positive deflection, and Q,S have a negative deflection? I don’t understand why this is.

  58. dpsicose February 28, 2012 at 4:43 am #

    Can anyone explain why P,R,T have a positive deflection, and Q,S have a negative deflection? I don’t understand why this is.

  59. PrettyHair09 March 1, 2012 at 5:31 pm #

    Is there a video that show when SA node and AV node fire, when atria relax, when the ventricle relax, when valves open and close, and the points where ventricle pressure and volume is high or low? I really need help with that.

  60. PrettyHair09 March 1, 2012 at 10:31 pm #

    Is there a video that show when SA node and AV node fire, when atria relax, when the ventricle relax, when valves open and close, and the points where ventricle pressure and volume is high or low? I really need help with that.

  61. Bjan4eto March 10, 2012 at 8:52 am #

    Nice I like this link, it helps me to realize everything that I studied for EKG .. thank you very much :)

  62. medcaueapg March 11, 2012 at 1:47 am #

    Good one. Thanks.

  63. medcaueapg March 11, 2012 at 6:47 am #

    Good one. Thanks.

  64. Aragon17E March 20, 2012 at 11:26 pm #

    too basic, but well done

  65. Aragon17E March 21, 2012 at 3:26 am #

    too basic, but well done

  66. sherab March 28, 2012 at 9:11 am #

    thank you very much. very good video and article. clear voice and easier to understand.

  67. sherab March 29, 2012 at 10:38 am #

    Hi my greatest teacher Leslie Samuel!
    Actually i’m a Tibetan monk who are studying human physiology at Emory university. and this is my second year, i just learned english for one year before i came to here. so my english is so bad and always get language problem in my classes. recently i found your TVs and articles which very clear and more easy to understand to me. then i got really happy. now i watch your videos and read your articles which relevant my classes before i go to the classes. it help me to understand what’s going no in the classes. thank you very much.
    sherab.

  68. gina rimbey April 4, 2012 at 12:39 pm #

    you are a great teacher! I can’t wait to take my test in school. thank you

  69. gina rimbey April 4, 2012 at 12:39 pm #

    you are a great teacher! I can’t wait to take my test in school. thank you

  70. Anonymous April 4, 2012 at 4:39 pm #

    you are a great teacher! I can’t wait to take my test in school. thank you

  71. gina rimbey April 4, 2012 at 4:39 pm #

    you are a great teacher! I can’t wait to take my test in school. thank you

  72. DocAvicenna81 April 6, 2012 at 5:46 pm #

    Thank You. This explanation is fantastic. Do you mind if I use this video to show patients in my Cardiology clinic? I would greatly appreciate it. Please advise. Thank You in advance.

  73. InteractiveBiology April 6, 2012 at 6:05 pm #

    Yes, you can do so. Thank you for using our videos. We hope your patients will find them useful and easy to understand.

  74. DocAvicenna81 April 6, 2012 at 9:46 pm #

    Thank You. This explanation is fantastic. Do you mind if I use this video to show patients in my Cardiology clinic? I would greatly appreciate it. Please advise. Thank You in advance.

  75. InteractiveBiology April 6, 2012 at 10:05 pm #

    Yes, you can do so. Thank you for using our videos. We hope your patients will find them useful and easy to understand.

  76. TheAsh201093 April 8, 2012 at 3:47 am #

    this helped me a lots.

  77. TheAsh201093 April 8, 2012 at 7:47 am #

    this helped me a lots.

  78. MsCooltoes April 10, 2012 at 1:34 am #

    Great teaching … thanks Leslie

  79. MsCooltoes April 10, 2012 at 5:34 am #

    Great teaching … thanks Leslie

  80. Fernando Orozco April 13, 2012 at 7:07 pm #

    Muy bien !!

  81. Shasha Khalid April 19, 2012 at 7:04 am #

    excellent!!!! i hd alot a problems regrading Ecg reading!!! but thanks to this video :)

  82. Anonymous April 19, 2012 at 11:04 am #

    excellent!!!! i hd alot a problems regrading Ecg reading!!! but thanks to this video :)

  83. Shasha Khalid April 19, 2012 at 11:04 am #

    excellent!!!! i hd alot a problems regrading Ecg reading!!! but thanks to this video :)

  84. HurricaneReaper April 23, 2012 at 1:49 pm #

    thank you man, really helped a lot.

  85. Amjad Ali April 23, 2012 at 3:36 pm #

    Done A Great Job/………………

  86. HurricaneReaper April 23, 2012 at 5:49 pm #

    thank you man, really helped a lot.

  87. Anonymous April 23, 2012 at 7:36 pm #

    Done A Great Job/………………

  88. Anti Evil April 23, 2012 at 7:36 pm #

    Done A Great Job/………………

  89. Anti Evil April 23, 2012 at 7:36 pm #

    Done A Great Job/………………

  90. Abdirahim Shide April 26, 2012 at 11:23 am #

    Wow great lecture

  91. Anonymous April 26, 2012 at 3:23 pm #

    Wow great lecture

  92. Abdirahim Shide April 26, 2012 at 3:23 pm #

    Wow great lecture

  93. Nicole Scott April 29, 2012 at 5:54 pm #

    this is really helping thank you!

  94. Anonymous April 29, 2012 at 5:54 pm #

    this is really helping thank you!

  95. Nicole Scott April 29, 2012 at 5:54 pm #

    this is really helping thank you!

  96. Haldouda April 30, 2012 at 3:50 pm #

    You are the man! Thank you loads Leslie…

  97. Haldouda April 30, 2012 at 3:50 pm #

    You are the man! Thank you loads Leslie…

  98. Maria May 9, 2012 at 10:57 pm #

    Lessley you have succeeded in making this site the best available biology resource in the whole world wide web and I mean it. I am preparing for an Axam in the next 2 hrs and you have no idea how much your lectures are helping me right now. Thank you for being a greater person having others in mind and not just your self.

    May God bless you for this

    • Leslie Samuel May 10, 2012 at 10:21 am #

      You are so very much welcome. Glad to hear the videos are helping you!

  99. mattex989 May 21, 2012 at 10:27 am #

    Great video – I’m doing my Para degree at the mo!

  100. mattex989 May 21, 2012 at 10:27 am #

    Great video – I’m doing my Para degree at the mo!

  101. pattaratidaa12 May 27, 2012 at 9:49 am #

    so where’s the repolarization of the atria? does it appear on the ECG?

  102. pattaratidaa12 May 27, 2012 at 9:49 am #

    so where’s the repolarization of the atria? does it appear on the ECG?

  103. anahita14 May 31, 2012 at 1:06 am #

    Atrial repolarisation is submerged within the much bigger QRS complex.

  104. anahita14 May 31, 2012 at 1:06 am #

    Atrial repolarisation is submerged within the much bigger QRS complex.

  105. yayo3036 June 22, 2012 at 11:36 am #

    thank you !

  106. yayo3036 June 22, 2012 at 11:36 am #

    thank you !

  107. albelaaaa44 June 30, 2012 at 4:56 pm #

    @ocbtalf you are correct. I was looking everywhere for the best way to put on huge muscles mass. Listen to this If you want something that builds huge muscle which showed me exactly what i was doing wrong. The video is public now. Have a look > bit.ly/Ks5n0K?=nbqtyx

  108. albelaaaa44 June 30, 2012 at 4:56 pm #

    @ocbtalf you are correct. I was looking everywhere for the best way to put on huge muscles mass. Listen to this If you want something that builds huge muscle which showed me exactly what i was doing wrong. The video is public now. Have a look > bit.ly/Ks5n0K?=nbqtyx

  109. albelaaaa44 June 30, 2012 at 4:56 pm #

    @ocbtalf you are correct. I was looking everywhere for the best way to put on huge muscles mass. Listen to this If you want something that builds huge muscle which showed me exactly what i was doing wrong. The video is public now. Have a look > bit.ly/Ks5n0K?=nbqtyx

  110. hisprincess1513 July 3, 2012 at 5:51 pm #

    I’m currently studying Cardio MedSurg in my nursing course and i was wondering could you make a video showing what the heart looks like when its in the different kinds of dysrhythmias? Its something i would be able to understand better if i can see how the heart beats during each kind. If you cant do you know where i can find a video like this?

  111. hisprincess1513 July 3, 2012 at 5:51 pm #

    I’m currently studying Cardio MedSurg in my nursing course and i was wondering could you make a video showing what the heart looks like when its in the different kinds of dysrhythmias? Its something i would be able to understand better if i can see how the heart beats during each kind. If you cant do you know where i can find a video like this?

  112. Mike July 11, 2012 at 4:27 am #

    What software and hardware do you use to make these videos? I’m about to go into medical school and I think it would be great if I could make videos as I go through school as a resource for people that follow behind me.

    If you could help me to learn the software – and I am able to make the videos without legal restrictions (or time restrictions), I would allow you to host a copy of the videos.

    Thanks!

    • Leslie Samuel July 21, 2012 at 9:54 pm #

      Hi Mike, I did a podcast episode about how I make my videos. You can check it out here.

  113. Mike July 11, 2012 at 4:36 am #

    Everyone is wondering – I just found the answer:
    “You might be surprised that ventricular depolarization (the QRS wave) and repolarization (the T wave) point in the same direction, although they are produced by opposite potential changes. This is because depolarization of the ventricles occurs from endocardium to epicardium, whereas repolarization spreads in the opposite directoin, from epicardium to endocardium.”

    Source: Human Physiology, By Stuart Ira Fox, Twelfth edition (copyright 2011) page 424

  114. missleezjy July 24, 2012 at 5:29 am #

    allow me… :)
    thanx(i downloaded it :) )

  115. missleezjy July 24, 2012 at 5:29 am #

    allow me… :)
    thanx(i downloaded it :) )

  116. missleezjy July 24, 2012 at 5:29 am #

    allow me… :)
    thanx(i downloaded it :) )

  117. gparks440 August 22, 2012 at 9:25 pm #

    what is a borderline ecg

  118. NileQueenAset August 26, 2012 at 8:14 pm #

    Thanks!

  119. TheSoniablue August 30, 2012 at 3:20 am #

    Thank you sire! I am gonna download this….;)…i did have problem in ecg interpretation a bit now cleared….but still wanna keep this video as a rememberance….and revision point for exams…thanks once again…

  120. gerardo101silva September 6, 2012 at 1:11 am #

    Thank you so much !

  121. havingfun122 September 24, 2012 at 2:32 am #

    awesome! wish Doctors here were like you. :) most of them here get offended if I even ask them what they understood and what they think they will do to combat the problem. :)

  122. havingfun122 September 24, 2012 at 2:37 am #

    thanks interactivebiology!.. the place where I live.. Doctors (most of them – actually every doctor I have met) do get offended if I even ask them what they are doing to combat a problem based on these readings..

  123. smergphy olaverria October 2, 2012 at 10:44 pm #

    i think i love you! you are my hero! :) please keep the videos coming!!!

  124. tropolek October 28, 2012 at 10:57 am #

    usless shit

  125. Mikejohn177 October 30, 2012 at 3:24 pm #

    interesting!

  126. nissansentraglx November 12, 2012 at 1:36 am #

    am looking to be trained as an ekg tech. this helped.

  127. SyriusY November 12, 2012 at 10:10 pm #

    this is incredible. i have a test paper at medicine tomorrow and this video made the thing a lot easier

  128. Squism Chaser November 19, 2012 at 3:55 am #

    Outstanding. I sat through a two hour lecture and I was more confused than when I came in. This is straight to the point and very clear. Thanks.

  129. Unbeatable1912 November 25, 2012 at 8:01 pm #

    One word. Incredible.

  130. Dufflebag Keem November 27, 2012 at 2:31 am #

    Awesome video!! Great way of breaking down the information it really helps.

  131. alexeo111 November 27, 2012 at 4:50 pm #

    It can be recognised not by using conventional ECGs but during some specialised electro physiology tests when both the atrial and ventricular waves are separated

  132. SCSUguy85 December 5, 2012 at 6:55 pm #

    Love this thanks for posting the video. I’m going into emergency medicine and this helps me understand EKG PQRST waves a lot better then what I learned in class!

  133. lponced2002 December 11, 2012 at 12:24 am #

    I’m currently in pharmacy school and every one of your heart videos has helped me more than the lectures of my professors. thanks!

  134. TwoMegans December 11, 2012 at 7:14 pm #

    Extremely helpful thank you so much :)

  135. Kirill Andrienko December 19, 2012 at 8:28 am #

    Very nice explanation (need some drilldown to medical topics)

  136. rodrigonewton December 20, 2012 at 8:04 pm #

    Hey Leslie, amazing video ! I’m not a Biology enthusiast (by the way, I’m an engineer), but you got my attention during all the explanation… You were born to teach and help others to understand things !! Keep it up man !! Congrats !

  137. A.S.Fathima Rizwana Salam December 21, 2012 at 3:19 am #

    so thanks of you…. am not a doctor but an engineer … for my project sake i just cme across this ….. very crisp and clear

  138. Maha772 December 25, 2012 at 8:15 pm #

    This Chanel always saves me. Thank you!!!!

  139. masaari234 January 1, 2013 at 12:48 am #

    this was great!

  140. Azmat Yousafani January 1, 2013 at 11:35 am #

    Your videos are quite helpful. Can you please explain the terms depolarization and repolarization in simple words?

  141. JNHstudios January 3, 2013 at 8:27 pm #

    see episode 9 or 10. :)

  142. nadia41683 January 5, 2013 at 10:52 am #

    Thank you so much! This video was great and supper easy to understand ;my book was confusing me.

  143. caramelje22 January 5, 2013 at 4:06 pm #

    I enjoyed #048 how to read ECG. But could you do another video in more detail. I like how you teach and I would like to become better at reading the ECG. Maybe like a video for 10mins or so all about ECG/EKG..thank you again for all your videos!!

  144. Tasha Foy January 12, 2013 at 9:53 pm #

    Thank you! Fantastic teaching – clear and to the point.

  145. Shinitha Ebenezer January 16, 2013 at 4:11 pm #

    thank u

  146. Tarmizi Mohd January 19, 2013 at 2:35 am #

    Thank you…

  147. Alpi1998 January 21, 2013 at 4:37 pm #

    Thank you for the interest and helpful video

  148. Sadie W January 29, 2013 at 6:31 pm #

    Thank You so much….I have read and reread this chapter. You made it make sense.

  149. Jorge Viana January 29, 2013 at 11:33 pm #

    SI SOS MEDICO O ESTUDIANTE DE LA SALUD!! NO TE PODES PERDER EN MI CANAL
    DALE ME GUSTA Y SUSCRIBITE PARA RECIBIR LOS VIDEOS Y MEJORE EL CANAL! NO TE PIERDAS LOS ULTIMOS VIDEOS DE EJE HEXAXIAL EN ECG

  150. Hussein Almussawi February 4, 2013 at 9:28 pm #

    this vidio help me more………thank you and i with for you the best

  151. Ted P February 6, 2013 at 6:36 am #

    I have hard time learning to figure out the heart rate by the rule of 300 of ECG , is there anyway you upload video show me the easy way to learn.

  152. JDTrojan10 February 7, 2013 at 9:11 pm #

    I thought U wave was indicative of hypokalemia.

  153. Pedro Gh February 8, 2013 at 7:24 pm #

    fantastic!!
    i’ll use it in my school conference

  154. Pat Perp February 9, 2013 at 5:05 am #

    Interactive biology: are you the instructor for Jefrench?

  155. raykupal February 14, 2013 at 5:43 am #

    thank you for this video. this will help my wife in getting her ACLS cert.

  156. jdubeification February 14, 2013 at 3:17 pm #

    Thank you for your video! I’m a nursing student and appreciate your eagerness to share your knowledge.

  157. 23brenbren February 17, 2013 at 4:32 pm #

    spanish please!!!

  158. VR6BLAIZE February 19, 2013 at 9:22 pm #

    brilliant thank you so, clean and simple to understand

  159. simone84gabriel February 20, 2013 at 6:03 pm #

    I would to say thanks .You been helping me out so much is my classes.keep up the good work lol

  160. Jose Suarez February 21, 2013 at 2:22 pm #

    When does the Atria repolarize>??

  161. mooreal5 February 24, 2013 at 5:20 am #

    During the depolarization of the ventricles. Due to the large signal the ventricles send out, you just can’t see it :)

  162. Ladyknight C February 24, 2013 at 8:09 pm #

    I love this guy’s videos. They help me a lot when I study for my A&P exams.

  163. Kareem Latif February 28, 2013 at 2:55 am #

    Thank you so much for these videos, they are such a huge help!

  164. Brenda Jedra February 28, 2013 at 3:41 pm #

    I love these videos! Thank you so much for taking your time to teach. They are so helpful and explain things that the instructors are not in class!

  165. Hồ Thuý Mai February 28, 2013 at 10:15 pm #

    Thank You.

  166. kittywaymo March 4, 2013 at 9:33 am #

    Awesome!

  167. julieisonfire7 March 7, 2013 at 6:54 pm #

    how to calculate the p wave altitude?

  168. skimmer521 March 10, 2013 at 11:01 am #

    sam is hot.

  169. priyalji March 14, 2013 at 4:42 pm #

    during the QRS complex. which is why you don’t see a wave for it. (If I’m not wrong,what I got from lecture) .

  170. TTerminatorr March 16, 2013 at 12:32 am #

    Another simple let great video.

  171. Kanhaiya Bheergoonath March 20, 2013 at 1:27 pm #

    Remember AVDA
    A- Atrial systole (depolarisation of atria/contraction of atria/P)
    V-Ventricular Systole (depolarisation of the ventricles/contraction of the ventricles/P)
    D-Diastole (repolarisation of the ventricles/relaxation of both atria and venticles/QRS complex)
    A– Atrial systole (depolarisation of atria/contraction of atria/P)-ommiting U
    Correct me if I’m wrong or thumbs me up for others to see.

  172. Politicsgetmenkilled March 24, 2013 at 2:30 pm #

    Thank God a man that speaks english and knows more than my college teacher. Daymar College EKG class is awful because of the teacher. I’ve learned more on these videos than the teachings at the school. Thank you!

  173. xHaniffax March 25, 2013 at 9:58 pm #

    Hey man, are you guyanese?

  174. Rhonda Junaid March 28, 2013 at 3:08 pm #

    another great video! I learn more from this than actual lecture in class…(=^D

  175. elf3l1f March 28, 2013 at 11:46 pm #

    thank you soooooo much!!!!

  176. Micah Espina March 30, 2013 at 11:41 pm #

    Hello everyone. Very good clip. My close friend had been a flabby. He reworked himself from 293 lbs of pure fat to 205 lbs of natural lean muscle. I realized I was dumbfounded. I just signed up personally as I’m working to get enormous muscle mass. He made use of the Muscle Building Bible (Google it)…

  177. sumbukids April 2, 2013 at 3:42 am #

    Excellent the videos have helped me so much this year. Thank you.

  178. shima Alhaj April 5, 2013 at 4:47 am #

    thank you alot doc

  179. pinknurse101 April 11, 2013 at 7:18 pm #

    You make understanding EKG really easy! This is what exactly I’ve been searching for! Thanks a lot!!!

  180. MikahSK April 13, 2013 at 2:46 pm #

    awesome video tnx

  181. Jayatissa Deweddana Gamage April 20, 2013 at 9:25 pm #

    It would be a shame for you not to get ripped when these normal people accomplish it easily using Atomic Fat Loss (check it out on Google).

  182. raziagloop95 April 22, 2013 at 9:12 am #

    Omg you just made it seem so simple than what my biology book was blabbering on about.

  183. MissAwesome258 April 23, 2013 at 11:17 am #

    what does it mean when the P wave is inverted?

  184. essamhaitham April 30, 2013 at 2:28 pm #

    the u wave is due to contraction of the papillary muscle .. small,positive, and rare wave
    and the atria Re-polarization is masked by the stronger QRS complex ( ventricles depolarization ) because they happen at the same time ;) ..hoped i helped

  185. JUDY HERNANDEZ May 11, 2013 at 12:37 pm #

    I was told that the U wave is due to electrolyte imbalance

  186. jgdjshfshdhfsdhfs May 18, 2013 at 3:47 pm #

    some sort of action potential but for what????

  187. Raymond Palmer May 28, 2013 at 6:44 am #

    That the direction of electrical depolarization is retrograde to what it normal is. When seen in lead 2, it implies the vector is moving away from Lead 2 (when you think of Einthoven’s triangle)

  188. Womb2Tomb1 June 5, 2013 at 10:04 am #

    excuse me how come the t wave is repolarizing if the hump is going up isnt that depolarization?

  189. innocentloyal June 14, 2013 at 3:12 pm #

    Could you do a video on what an ekg look like when the leads are placed on backward.

  190. naldus1 June 21, 2013 at 3:02 pm #

    the vector is going in the opposite direction than of depolarisation. thats why it is upward.
    Source : Guyton.

  191. jovan abdul-mawjud July 21, 2013 at 9:55 pm #

    NICE NICE NICE . Thanks a lot sir …

  192. SUSY SANCHEZ August 7, 2013 at 6:21 pm #

    THANK YOU VERY GOOD INFORMATION !!!!

  193. Blundo blunden August 7, 2013 at 9:26 pm #

    its safe to say your bloody fantastic!! i reckon ive passed all my previous subject because of you!

  194. Lisa Baizura August 14, 2013 at 4:14 am #

    good explanation… tqvm

  195. TheAllahgreat September 10, 2013 at 7:51 am #

    good

  196. Dilip Kumar Pradhan September 12, 2013 at 1:45 pm #

    nice for learners

  197. vandana467 September 13, 2013 at 2:18 am #

    gud explanation

  198. Alexander Beliasvky October 12, 2013 at 10:12 pm #

    thanks for this video

  199. nouss mo October 15, 2013 at 8:41 pm #

    can you tell me what is the difference between a QS wave and a necrosis Q wave

  200. Ove October 15, 2013 at 11:17 pm #

    This might come as a stupid question but why doesnt the atria repolarize? Is this somhow masked by the QRS complex? Like if its inside/behind the QRS complex. Is this wrong? Or is there some other explanation?

  201. Fred Johansson October 16, 2013 at 11:58 am #

    that is correct

  202. Maggie Dippold October 20, 2013 at 12:24 pm #

    It is masked by the QRS complex

  203. Maggie Dippold October 20, 2013 at 12:24 pm #

    It is masked by the QRS complex

  204. Kaveen Amarathunga October 26, 2013 at 4:47 am #

    If you seriously want to burn up fat fast, you should do a google search Nifty Fat Blaster. They can guide you and help you get the body you deserve.

  205. TEJ PRASAD BHATTARAI October 27, 2013 at 7:30 pm #

    Have you heard about Legion Fat Loss? (Google it) It is a quick and easy way to get rid of fat fast.

  206. TheRainbow54321 October 31, 2013 at 6:29 am #

    Thanks! (y)

  207. Mohammad Zia October 31, 2013 at 10:30 am #

    Hello everyone. Fabulous vid clip. My bro was once obese. He went from 285lbs of fat to 201lbs of complete muscle mass. His mates were shocked. I just signed up myself because I need to enhance my entire body. He made use of the Muscle Building Bible (Look in Google)…

  208. search engine optimization May 8, 2014 at 5:09 am #

    Do you have a spam problem on this website; I also am a blogger, and I was
    curious about your situation; we have created some nice methods and we are looking
    too swap strategies with other folks, why not shoot me an e-mail if interested.