tag:blogger.com,1999:blog-549949223388475481.post377001045727981809..comments2024-03-28T14:02:08.119-05:00Comments on Dr. Smith's ECG Blog: A very fast wide complex tachycardiaUnknownnoreply@blogger.comBlogger8125tag:blogger.com,1999:blog-549949223388475481.post-8808523072108618602020-06-13T14:08:53.055-05:002020-06-13T14:08:53.055-05:00Thanks for your comment. To my knowledge this pati...Thanks for your comment. To my knowledge this patient was NOT on a 1C drug prior to coming to the ED. Clearly, AFlutter with 1:1 AV conduction would have risen to the top of our differential if he had been on a 1C drug! — :)ECG Interpretationhttps://www.blogger.com/profile/02309020028961384995noreply@blogger.comtag:blogger.com,1999:blog-549949223388475481.post-90649498367400439182020-06-13T03:41:54.056-05:002020-06-13T03:41:54.056-05:00A very challenging diagnosis with excellent manage...A very challenging diagnosis with excellent management (=synchronized cardioversion).<br />As to the diagnosis of this very fast WCT in this 60-year old patient, I initially disregarded the diagnosis of VT due the presence of the typical LBBB morphology (importantly with fast initial ventricular activation, a finding favouring a SVT rhythm and thus against VT). But, without excluding VT at all, I would immediately contemplate also the Bundle Branch Reentry tachycardia (this arrhytmia fits well with the severe LV disfunction): this is my second diagnostic choise, though I would have expected a beseline ECG with much more significant abnormalities (namely, conduction defects).<br />While aknowledging that there is not any certainty, my first diagnostic choise is 1:1 atrial flutter caused by 1C-drug (Propafenone, Flecainide) effects; this is based just on the above my considerations and on my experience since I have seen a few those cases in patients treated with 1C-drugs and without taking beta-blockers.<br />Great case!Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-549949223388475481.post-61045112902991365672020-06-10T06:55:47.652-05:002020-06-10T06:55:47.652-05:00@ Jerry — CORRECT. I think this is precisely why y...@ Jerry — CORRECT. I think this is precisely why you so very carefully worded your statement (last bullet before your Summary in my Addendum above): “If the WCT in today’s case was due to antidromic conduction in a patient with an accessory pathway — then I’d expect to see evidence of ventricular preexcitation on the post-conversion ECG. But it’s not there ... “. The fact that no delta wave is seen after conversion to sinus rhythm only means that at this normal heart rate, conduction goes through the normal AV nodal pathway. This of course says nothing about the possibility of there being a “concealed” AP that is not going to be seen during sinus rhythm — because conduction only occurs retrograde in that “concealed” AP. But since the most dangerous tachyarrhythmias in patients with WPW are the very rapid AFib and AFlutter rhythms because they conduct anterograde (with risk of conducting very fast rates to the ventricles) — lack of a delta wave in the post-conversion tracing IS indeed reassuring that risk to the patient is less. THANKS so much for your insights! — :)ECG Interpretationhttps://www.blogger.com/profile/02309020028961384995noreply@blogger.comtag:blogger.com,1999:blog-549949223388475481.post-70952208018524896352020-06-10T06:14:29.566-05:002020-06-10T06:14:29.566-05:00Ken...
Regarding my comment about expecting to se...Ken...<br /><br />Regarding my comment about expecting to see delta waves in the post-cardioversion tracing, it is true that some people with pre-excitation do not normally manifest any delta waves on their ECGs. However, that is due to the fact that in those cases the AP either conducts only in a retrograde manner (concealed pathway) OR that the AP conducts in an antegrade direction but only very slowly - more slowly than the AV node (not every AP is superfast!). In those cases, the patient will not be at risk for rapid, destabilizing wide complex tachycardias. The AV node will dominate the depolarization of the ventricles.Jerry W. Jones, MD FACEP FAAEMhttps://www.medicusofhouston.comnoreply@blogger.comtag:blogger.com,1999:blog-549949223388475481.post-58154225565847260672020-06-09T14:34:32.749-05:002020-06-09T14:34:32.749-05:00@ Subhasish — THANKS for your comment. I agree ent...@ Subhasish — THANKS for your comment. I agree entirely with you that it would help for us to see the period of ECG monitoring during and immediately after adenosine administration (Plese see the “P.S.” in My Comment above, which is the very last paragraph that I wrote).<br /><br />YES — We include the possibility of AFlutter with 1:1 AV conduction without a bypass tract (in which case, QRS widening would be the result of rate-related LBBB aberration — since no BBB is seen on the post-conversion tracing). There is no mention of ongoing antiarrhythmic use in this case (I assumed the patient was not on Flecainide — but I don’t know details of the history).<br /><br />As to treatment with Flecainide — YES, it can be effective in converting AFlutter — but “Ya gotta be there” if you choose to opt for additional antiarrhythmics (such as IV Flecainide) in a patient with a wide tachycardia at 268/minute with a lowish BP, who failed to respond to adenosine. I’d favor cardioversion — which was done and which was successful.<br /><br />As per my answer to the question just above you — the frontal plane axis in ECG #1 is not inferiorly directed (it is instead a superior axis, the QRS being predominantly negative in leads III and aVF) — therefore not manifesting a QRS morphology suggestive of RVOT VT — :)ECG Interpretationhttps://www.blogger.com/profile/02309020028961384995noreply@blogger.comtag:blogger.com,1999:blog-549949223388475481.post-86476745590542571912020-06-09T14:25:33.470-05:002020-06-09T14:25:33.470-05:00Hi. Outflow Tract VTs (most commonly RVOT VT, but ...Hi. Outflow Tract VTs (most commonly RVOT VT, but occasionally LVOT VT) generally manifest an inferior frontal plane axis — because the rhythm originates from “above” (where the outflow tract lies) — and travels downward. In my Figure-1 above — I’ve drawn in a RED vertical line in leads I,II,III to indicate the onset of the QRS — and a BLUE vertical line to indicate the end of the QRS. It can be seen in lead III of Figure-1 (with a similar picture being seen in lead aVF) that the QRS complex is predominantly negative within these 2 vertical lines — therefore, the frontal plane axis for ECG #1 is leftward and superior. One does not expect a superior axis with Outflow Tract VT. For an example of RVOT VT (with a LBBB pattern in the chest leads and inferior frontal plane axis) — Please CHECK OUT the Feb. 5, 2013 post — http://hqmeded-ecg.blogspot.com/2013/02/regular-wide-complex-tachycardia-what.html — :)ECG Interpretationhttps://www.blogger.com/profile/02309020028961384995noreply@blogger.comtag:blogger.com,1999:blog-549949223388475481.post-83291160835540073552020-06-09T13:38:48.638-05:002020-06-09T13:38:48.638-05:00Although adenosine did not convert the arrhythmia,...Although adenosine did not convert the arrhythmia, a recording of ecg during adenosine administration would be helpful to look for unmasking of flutter waves. <br />Atrial flutter with 1:1 av conduction is possible without a bypass tract also especially when patient is on chronic oral Flecainide without a beta blocker or rate limiting ccb. <br />Since patient is relatively stable iv Flecainide could have been tried as it works both in atrial flutter and svt. <br />The width of qrs and failure of adenosine notwithstanding ,is outflow tract VT (lbbb morphology ) a possibility? Subhasish Singh herehttps://www.blogger.com/profile/18022600313880536118noreply@blogger.comtag:blogger.com,1999:blog-549949223388475481.post-81700465769668729332020-06-09T10:37:46.500-05:002020-06-09T10:37:46.500-05:00Great post Steve. Had a similar ddx but also thoug...Great post Steve. Had a similar ddx but also thought about RVOT VT given LBBB and inferior axis. Any reason why this cant be RVOT VT?Who is writing this?https://www.blogger.com/profile/04263291673560984779noreply@blogger.com