Ten Minute ECG (Part 2)--Okay, It Is 20 Min But I Tried

This movie is an attempt to give foundational knowledge on how the electrocardiogram (ECG) picks up the cardiac conduction cycle of the heart. The cardiac conduction cycle is explained, lead systems are discussed, and how the leads pick up the voltage changes in the cardiac conduction cycle is described. My hope that the video will help you understand precisely how the ECG works so that you can adapt that knowledge to understand how changes in the ECG reveal abnormalities in the heart. The video is intended for freshman/sophomore pre-nursing students.

A copy of the diagram can be viewed at http://www.kirkwood.edu/pdf/uploaded/695/ecg_layout_side1.pdf
http://www.kirkwood.edu/pdf/uploaded/695/ecg_layoutf_side2.pdf

Category:

Education

Tags:

• ECG
• EKG
• electrocardiography
• 12-lead
• heart
• electrocardiogram

[rkoz543]

Your ECG videos are great! I have watched many of them this morning. You mention in this video that the document you are working with will be available through a link and that there is a file that we can download to work through the problems. I am not finding a link for that. Where would that be?

[hennagerdj]

@rkoz543 I am sorry I am so late in replying, did you find the links. You need to open up the more info and the links to get the files will be revealed. Take care, dj

[hennagerdj]

0marius0. I agree that the way you describe this is the way it is often taught, but I want to question that way of teaching it. Depol. and repol. are the same voltage change so they should be recorded equally. Some propose that atrial repol. is concealed by the QRS, but the atrial action potential is too brief to reach into the QRS. It is actually the length of the p wave.

[hennagerdj]

Please take a look at the bem book. They have a figure that shows the length of action potentials form various cells in the heart. That is the figure that convinced me to teach it this way. I hope it explains it for you as well. Thank you, dj

[0marius0]

I perfectly understand your point of view, but I would like to make you notice 1.6 figure in the book ,,Investigative Electrocardiography in Epidemiological Studies and Clinical Trials''. the picture shows the depolarisation in the atrium wich has a direction shift that the red arrow in your diagram doesn't have. this direction change would explain the whole p wave as due to depolarisation.

[hennagerdj]

That is a head scratcher that I will have to think about. Your point is well taken but I had focused on figure 1.2 of the book where depol appears to go up the p wave and repol goes down. I also like fig 1.7 of the bem book as it led me to the same conclusion. I like that you pointed out that fig 1.6 predicts the biphasic p wave, but then I am left wondering why the P-Q segment is not below baseline. I appreciate your discussion, I am really trying to make this teachable :). Thank you.

[wolflauren]

The T-wave in lead III should have a positive deflections. This is because the epicardial cells repolarize before the endocardial cells. The "negative" action of repolarization is in the direction of the negative electrode, producing a positive deflection on the ECG. 8 years of experience with analyzing ECGs in the field as a paramedic also confirm this knowledge: in leads I, II, and III all components should have a positive deflection unless there is ischemia or injury present.

[YYCH2o]

I wrote four pages of notes from my textbooks without being able to wrap my brain around any of it until now. Thank you for the great videos and slides.

[gnagaraj87]

Thanks for the excellent instruction!

[mlknight14]

the heart diagram in the beginning looks like a mudkip! XD

[r87y]

Excellent videos! i really appreciate you sharing this. 

[ravi14213]

u showed repolarisation in ekg part 2 abt lead rules in opposite direction of depolarisation but in this video u confused me by showing both in same direction could u explain please

[abhijitmsm]

offcourse its awsome short basic way u explained

[Serpico261]

hi there, im sure there is a mistake in the chart "Investigative Electrocardiography in Epidemiologial Studies and Clinical Trials." as far as i learned the atrial repolarization is overlaided by the QRS complex which doesnt show the atrial repolarization...the PR segment shows the completion of atrial excitation

thanks for your vids my friend

[props4peeps]

thank you SO MUCH. i greatly appreciate your passion. I was curious about the actual 'how does' myself and being in anphy 102, it wasn't something deemed necessarily worthy of explaining in depth and guidance as you explained. Thank you again!