I drew the P waves from this lecture on a large piece of paper for students in my most recent 12 lead class to illustrate the concept of atrial enlargement. The student feedback was very positive and requested the p wave paper drwaings be incorporated into the ppt lecture. I think this is just further evidence that the info presented is very clear and valued by beginning 12 lead students! thank you!
really so helpful! just putting the heart in the ribcage and showing the vector movements for each change makes understanding it so much easier. thanks!
Thank you- this was a very helpful review. I am a nurse that will teach this to other nurses. The pace of the lecture was good, clear and to the point. Thank you- the information I gained from the video will help me be a better teacher (I hope).
Thank you very much Dr Strong. It is very very helpful. My previous knowledge of EKG probably ,I could tell that this tracing call EKG :) now I could somewhat tell of chamber enlargement .
@ho littleho, none of the EKG tracings are upside down. However, a prior commenter was thrown off the orientation of the heart in the diagrams showing the relationship of the heart to the precordial leads (which is what I suspect you are referring to). That view is an axial cross section in which the front of the heart is at the top of the picture, and the heart's left side is on the right side of the screen. This view was unexpected and a little disorienting to me the first time I saw it, but it is the standard used in cross sectional anatomy, including CT and MRI scans. I know that some people would prefer the more intuitive view with the heart at the bottom, but for better or worse, convention puts it at the top. Hope that helps!
I still don't understand what the complex represent in RVH. My understanding is that in RVH 1. left to right septum depolarization 2. ventricular depolarization to the right. So shouldn't v1 show a rR' complex and qQ' complex in v6? What does the q wave in V1 and R wave in V6 represent?
Amazing video. Still struggling to grasp the interpretation aspect that was demonstrated at the end. I struggle to apply the systematic approach to interpreting to Rhythms.
I rather want to know what atrial repolarization wave is called (Ta????)wave and why it isn't seen in morbitz type ii or type 3 ab block and is there any correlation like secondary repolarization abnormalities like T waves. Would be thankful for this.
Hi Dr. Strong, In the first example of RAE, why aren't any appropriate changes seen in lead V1? and If they would have appeared (>1 small box) would it increase the likelihood of a RAE based on the EKG?
I'm not sure which "first example of RAE" you're referring to, but the explanation is likely that the V1 changes expected in RAE (ie large initial positive deflection) have only 10% sensitivity (from Tsao et al paper Dr Strong references). In other words, the absence of V1 changes does not in any way help rule out RAE. It's only useful to rule RAE in (96% spec).
That's a great question! I would frame the problem slightly differently: how to diagnose hypertrophy in the presence of bundle branch blocks. Bundle branch blocks are generally diagnosed using the same criteria as usual. However, since blocks impact QRS voltage (RBBB causes tall R waves in V1, LBBB cause deep QS complexes in V1), and blocks cause secondary repolarization abnormalities morphologically similar to hypertrophy, separating block alone from block + hypertrophy can be very difficult or impossible. I suspect someone has published some form of criteria or rules for determining this, but I've never heard anyone discuss them.
Hi Sir, In RVH, there is a "q wave" in V1 lead. How does it form? Bcoz septal depolarisation should be +ve in V1, as it moves towards V1. Thank you in Advance :)
I had the same question. In RVH, there's a Q wave in V1 and prominent R (and absence of physiologic septal Q) in V6, suggesting in RVH the initial (septal) summation vector is toward the LV. Why would this be? Due to faster initial conduction in the left bundle when the RV is hypertrophic? Thanks for these.
hello, Dr, I would like to say that your youtube lessons have helped me alot, Im a 6th year med student and our classes on ECG were very poor since inthe hospital were I was working there was only one electrocardiogram and it belonged to the cardiologist who then left... I just wanted to ask you to increase the volume in your videos as the sound is very low and if you could provide exam exercises for us to work out?
This was amazing, I finally understand EKGs for the first time ever despite EKGs being "taught" to me numerous times before. Thank you for sharing your knowledge, Dr. Strong. You are a great teacher :)
DODesertDweller, you're right that If a patient has evidence of RVH, and also has tall R waves with T wave inversion in V6, if would certainly suggest concurrent LVH. However, I don't think the RVH example shows these findings. I think u might be looking at a different lead?
Complicated explaination.....better make it simple......at the end of video gained nothing...just kidding excellent piece of work Dr,,,thanks for sharing valuable information with us.
M having a doubt in RVH how come a deep S wave is formed in V6.. If the deep S wave is due to net deflection of vector towards right side then how come a positive 'r' wave is formed in V6? Its is due to? At the same time in RVH in V1 there will be tall R wave follwed by a small s wave . This s wave is due to ?
Thanks for the great lecture, Dr Strong. Why in the discussion of RVH represented in the precordial leads do we see the initial positive deflection in V6? I would have expected a QS wave in V6, with no positive deflection: that is, the initial septal depolarization (physiologic Q), followed by the deeper negative deflection of RV depolarization, with the "electrically humble" left ventricular wave subsumed/concealed within the deep negative S wave. The early R wave/positive deflection in V6 suggests at some point (after septal depolarization?) that the summation vector is decidedly toward the LV, then reverses toward the hypertrophied RV. Does the normal-size LV depolarize faster than the hypertrophied RV, such that early in the QRS complex the summation wave is toward V6? Is conduction in the LBB faster than in the RBB? In conduction less efficient in a hypertrophied ventricle? Does the degree of RVH affect the precordial QRS complex, ie in a massively remodeled RV (or a newborn's), could we see the LV wave fully subsumed in the RV wave? Finally, in RVH, why have we lost the septal depolarization wave in V1 and V6, with the first deflection representing LV depolarization?
Thank you so much for these great lectures. Would you be able to post pdf slides on your google drive for all your lectures (or at least for the EKG ones)? They would greatly enhance what is an already brilliant lecture series. Cheers, Jason
This series is awesome especially for those re-entering into healthcare like myself. Dr. Eric provides both book and online resources in addition to his lectures., One should feel confident with their skills after completing the course. Bravo both thorough and well done, thank you Dr. Eric
I was able to solve most of the tracing on the ecg paper, but ngl, i still find it difficult... honestly speaking... ecg is the hardest thing in medicine for me... I am just going to cross my fingers during my finals.
Thanks for pointing that out. I think there used to be an annotation calling attention to that error, but then frustratingly RU-vid got rid of all annotations years ago.
Dr. Strong, thank you so much for all this great lessons. I have only watch´t nine of them so far, this is truly one of the best training that one can get on RU-vid. This is helping a lot in my paramedic training. All the best from Iceland.
Did I get that right? ....Nearly all studies were done before echocardiography entered into common usage and many therefore utilized LV mass measured directly at autopsy as the gold standard.... shiver... That must have been long studies then... (I hope they didn't speed up the process) ... :)
Many thanks Dr Eric, what takes dozens of books to read is clearly and systematically arranged for such easy learning here.its helped me so much, i can safely say i can properly read an EKG thanks to you.
Thank you for the great series of videos! One question about the part of intrinsicoid deflection in LVH: On the example given, is there any relevance on the notch found on the abnormal QRS complex to suspect LVH or should we focus mainly on the intrinsicoid deflection duration itself?
I love your video series. It would be great if you would have a step wise technique for reading EKG's. for example step 1 find the axis, step 2 look at these leads and so on. Again thank you for your videos.
Thanks for the suggestion! A video on my recommended stepwise technique is on my shortlist for upcoming videos. Realistically, it will probably be posted by early March or so (though hopefully sooner).
Hello Dr Strong, excellent lecture - just one thing for my emphasis that at 10:42 when u said that the area under the curve enclosed as positive deflection should be more than 1 small square - but the colored area represents one large square - i did not understand that point - please would help a lot if u can answer that for me - appreciate.
Can anyone tell me why does q wave appear in V1 following RVH? you can see that at normal state it is absent (which makes sense), but why suddenly it pops out??
Hi, thank you for the video, that's very pedagogistic. However, I have a question : I don't understand why, in the RVH, you have a Q wave which is negative. If I have well understood, this wave is the septal depolarisation which is in direction to the right ventricule, why does it change during the RVH ? Thank you.
Hi, I am just wondering, in LVH the initial physiological q wave in V6 is often missing, and in RVH there is an initial small negative deflection in V1 (instead of the small positive deflection indicating septal depolarization), what is the cause of these changes? Does hypertrophy of either ventricle change the directionality of the septal depolarization? Your tutorials are brilliant btw,
Kim Ollivier Those are both great questions! The bottom line is I don't actually know why the details of the morphology of the QRS complexes in LVH and RVH don't always conform exactly to what one would predict. In the case of the missing septal q wave in LVH, I'm guessing it's because the left side of the interventricular septum (i.e. leftward of the left bundle) is hypertrophied enough that the depolarization vector leftward from the left bundle is greater than that of the vector directed rightward from the left bundle. (hard to explain without being able to draw it out - wish RU-vid allowed uploading photos in the comment section!). Unfortunately, I can't offer an explanation as to why there is sometimes an initial negative deflection in V1 in RVH - I agree that it doesn't make sense.
exactly my question, as according to how the electrical activity moves from right then left in ventricle. IN RVH in V1 there was initial Q deflection pointing the left ventricular depolarization but in normal the upward election R wave in V1 is right ventricular depolarization IN OTHER WORS HOW COME THE LEFT VENTRICULAR DEPOLARISATION IN V1 IN RVH COMES BEFORE THE RIGHT VENTRICUALR REPOLARISATION IN CONTRAST TO NORMAL LEAD IN V1 IN WHICH THE RIGHT VENTICULAR REPOLARIZATION COMES BEFORE.
Great video! Amazing teaching skills. At 8:13 - If somebody has a left atrial enlargement, I could see this also on lead I's p wave, which should have now a higher amplitude, right? 25:46 - lead II has a r wave (major ventr. depol.) and a deep S wave (basal ventr. depol.), both due to the LVH as well? R because of the shift, S because of the incr. number of cells? BTW it is "one specific criteriON" :-)
Dr.STONG,THANK YOU VERY MUCH.YOUR EKG LESSONS &THIER EXPLANATIONS , CLARIFICATIONS ARE EXRAORDINARILY IMPRESSIVE ON HEART CHAMBERS ENLARGEMENT &THEIR CLINICAL APPLICATIONS , SPECIFICITY, SENEITIVITY .I KNEW SO MANY KEY NOTES TO COME AT EARLY DIAGNOSIS OF HEART ENLARGEMENT & FOR LAST QUESTION I MY SELF DIAGNOSED EXACTLY PRIOR TO YOUR S CLARIFICATION . SO MANY THANKS.
The combination of other findings - borderline right axis deviation, poor R wave progression, low QRS voltage, and right atrial enlargement - are all seen in patients with COPD. Also, because of the combination of decreased QRS voltage and occasional mild rotation of the heart in patients with severe hyperinflation, ECGs of patients with COPD + RVH often don't look like the classic RVH (tall R in V1) that one might expect. Although this classification system is not widely used (or even known about), one historically prominent ECG reference has defined 3 subtypes of RVH, of which this COPD varient is one: books.google.com/books?id=EMH82LTrZI8C&pg=PA58&lpg=PA58&dq=chou+types+of+rvh&source=bl&ots=3LPHeN5Cq6&sig=ACfU3U3NMSfS9o5Ao-zaaMq5jcEwakGFjQ&hl=en&sa=X&ved=2ahUKEwiSrKmi9_noAhUDKqwKHf0tAg8Q6AEwCXoECBwQAQ#v=onepage&q=chou%20types%20of%20rvh&f=false
Great lecture. Often books have a schematic ecg portion showing only the findings. Your approach is better as we also get to know what and where to look. Very useful for clinical practice as well as for recent trend of post grad entrance exams in India (yup I'm from India) where they have introduced image based questions.These lectures not only give useful knowledge but also the confidence one needs to deal with ECGs in exams as well as in clinical practice. Kudos to you sir!
Hey Doc, great videos. I was wondering as a suggestion for new topics, if you could include videos on POCUS, basic bedside echo technique, image reading etc..? Would be awesome especially given your great teaching skills.
I recorded the video many years ago, so I can't say that I remember exactly why I chose those specific words...but having said that, I do find that most ECG learners know early on that 1 small box (i.e. 1mm) = 40 ms, while even among practicing clinicians, very few know the scale for the y axis. But if one were to be technical about the criteria, it is measured in mV and ms.
Hi Dr. Strong, I think there is a mistake at the final example of right and left atrial enlargement. Tall R wave in lead II as an example of RAE must be Tall P wave instead
Thanks. There is an embedded annotation pointing out the error, but unfortunately, annotation don't work when viewed on mobile devices, and others may have them turned off.
