tag:blogger.com,1999:blog-549949223388475481.post7341650309577553606..comments2024-03-26T22:42:04.176-05:00Comments on Dr. Smith's ECG Blog: Is it VT or SVT with Aberrancy?Unknownnoreply@blogger.comBlogger8125tag:blogger.com,1999:blog-549949223388475481.post-10097207061781613732020-05-12T05:39:29.207-05:002020-05-12T05:39:29.207-05:00@ Maarten — THANKS for your Question! My immediate...@ Maarten — THANKS for your Question! My immediate thought on see this tracing ( = ECG #1) — was that this regular WCT rhythm without sign of atrial activity was #1) VT; #2) VT & #3-thru-#9) VT. Only at #10) was “Something else” … And when dealing with VT — the finding of “extreme axis deviation” (which I define as a QRS complex that is ENTIRELY negative in either lead I or in lead aVF) is a strong supporting feature that the rhythm IS indeed VT (See the 2nd bullet in My Comment above). It’s interesting that in ECG #1, lead I doesn’t look that wide … but looking at simultaneously-obtained leads II and III tells us that a large part of the QRS in lead I lies on the baseline (so the QRS IS quite wide in this lead). And when you have VT — the general rule that lead V6 often has resemblance to lead I no longer holds — :)ECG Interpretationhttps://www.blogger.com/profile/02309020028961384995noreply@blogger.comtag:blogger.com,1999:blog-549949223388475481.post-53420404038987964712020-05-12T04:10:58.822-05:002020-05-12T04:10:58.822-05:00Based on the initial ECG, I thought there might ha...Based on the initial ECG, I thought there might have been switching of LA and LL leads, because morphology in I and V6 is so different! ECG#2 proved that wrong, but is there any way I could have seen this on the initial ECG?Maarten Van Hemelennoreply@blogger.comtag:blogger.com,1999:blog-549949223388475481.post-65603615729839546432020-05-10T07:49:42.608-05:002020-05-10T07:49:42.608-05:00I had the same question and the answer definitely ...I had the same question and the answer definitely makes sense to me. Thank you so much .<br />Dr Dahoumane. Algerian cardiology resident.Anonymoushttps://www.blogger.com/profile/02545780670806956102noreply@blogger.comtag:blogger.com,1999:blog-549949223388475481.post-16569064672495428692020-05-10T07:43:02.226-05:002020-05-10T07:43:02.226-05:00Thank you so so much . Very interesting post as us...Thank you so so much . Very interesting post as usual.<br />Anonymoushttps://www.blogger.com/profile/02545780670806956102noreply@blogger.comtag:blogger.com,1999:blog-549949223388475481.post-15094293563841706732020-05-06T16:09:14.681-05:002020-05-06T16:09:14.681-05:00The most common form of aberrant conduction is wit...The most common form of aberrant conduction is with RBBB morphology (with or without LAHB). What helps most in strongly suggesting aberrant conduction is if you have a completely typical morphology for RBBB — which consists of: i) an rsR’ in lead V1 in which the initial r wave is not overly tall, the S wave descends below the baseline, and you have a taller “right rabbit ear” [ie, a taller r’ deflection]; and ii) wide terminal S waves in lateral leads I and V6. But if you do not have both i and ii, — then the predictability of a RBBB-like pattern in V1 for aberrant conduction (or for preexisting RBBB) is very limited. The problem is that numerous exceptions exist, especially in patients who have underlying heart disease — so you may still have a RBBB pattern that looks “less typical” — and which doesn’t help much one way or the other. <br /><br />The QR that we see in lead V1 of my Figure-1 in this case, if anything favors a ventricular etiology because: i) the Q wave in V1 is fairly WIDE; and ii) the terminal R wave is wide and notched at the top. That said, in no way does this rule out the possibility of a patient who might have preexisting RBBB or RBBB aberration that is a bit atypical … BUT — there IS an unusual (all negative) QRS in lead I here + a monophasic notched R wave in lead V6 — and these features in lateral leads are VERY atypical for RBBB — so to me, it is QRS appearance in leads I and V6 (rather than in V1) that suggest a ventricular etiology.<br /><br />I hope the above makes sense — as this is not an easy subject to explain in words. I describe “My Take” on the subject in detail here — http://ecg-interpretation.blogspot.com/2012/05/ecg-interpretation-review-42-vt-brugada.html — IF you check out Figure 2 at that link, you’ll see pictures that illustrate what I am trying to describe — :)ECG Interpretationhttps://www.blogger.com/profile/02309020028961384995noreply@blogger.comtag:blogger.com,1999:blog-549949223388475481.post-56341063137510235512020-05-06T13:21:41.339-05:002020-05-06T13:21:41.339-05:00Great post as always !
Do you think that qR morph...Great post as always !<br /><br />Do you think that qR morphology in V1 favors VT rather than SVT ?Gilles Mugniernoreply@blogger.comtag:blogger.com,1999:blog-549949223388475481.post-6108552014900594032020-05-06T11:17:18.599-05:002020-05-06T11:17:18.599-05:00THANKS so much Mario! — :)THANKS so much Mario! — :)ECG Interpretationhttps://www.blogger.com/profile/02309020028961384995noreply@blogger.comtag:blogger.com,1999:blog-549949223388475481.post-86365649749216337652020-05-06T09:25:14.171-05:002020-05-06T09:25:14.171-05:00I would add some my thoughts on this very interest...I would add some my thoughts on this very interesting case.<br />As we all know, the specificity of all ECG criteria for VT is low when there is an underlying structural heart disease (and as result likely significant ECG abnormalities on patient's baseline ECG) but this is not the case here: despite chronic ischemic heart disease and despite ECG abnormalities on baseline ECG, the diagnosis of VT was made, thanks also to the other additional features magistrally illustrated by prof. Grauer. In this regard, I noticed that we were lucky to see on post-conversion ECG the presence of a PVC and especially a fusion beat, all the above providing further proves that this is VT: PVC with identical QRS morphology of VT is rather usual to see but a fusion beat is not! Great!<br /><br />Mario Parrinello<br />Anonymousnoreply@blogger.com