tag:blogger.com,1999:blog-549949223388475481.post5671215009073219957..comments2024-03-28T14:02:08.119-05:00Comments on Dr. Smith's ECG Blog: New Left Bundle Branch Block is a poor indicator of coronary occlusionUnknownnoreply@blogger.comBlogger10125tag:blogger.com,1999:blog-549949223388475481.post-7055474809768064972013-08-21T18:01:00.218-05:002013-08-21T18:01:00.218-05:00Charlie,
good observations!
1. Yes, you are right,...Charlie,<br />good observations!<br />1. Yes, you are right, there is LAFB.<br />2. Of course now all he needs to do is block his posterior fascicle and it is LBBB. Notice the rate is faster (75 vs. 60) when there is LBBB. There is probably a rate-related LPFB.<br />3. It constitutes incomplete trifascicular block. Full trifascicular block is 3rd degree heart block.<br /><br />thanks for your insights!<br /><br />Steve SmithSteve Smithhttps://www.blogger.com/profile/08027289511840815536noreply@blogger.comtag:blogger.com,1999:blog-549949223388475481.post-12809686054300344542013-08-21T12:26:02.225-05:002013-08-21T12:26:02.225-05:00Dear Dr Smith,
In case 2s 1st trace is left anter...Dear Dr Smith,<br /><br />In case 2s 1st trace is left anterior hemi/fasicular block present, with qR lead I, rS lead III and left axis deviation? Does this help explain the sudden change to complete LBBB? Are the conduction abnormalities likely due to LVH 2nd to the AS? Lastly does the presence of 1st deg AV block with LBBB constitute trifasicular block? (RBBB with 1st deg and R or L axis deviation often used for PPM indication in my area).<br /><br />Your blog = my bible<br /><br />CharlieAnonymoushttps://www.blogger.com/profile/16888292983934728491noreply@blogger.comtag:blogger.com,1999:blog-549949223388475481.post-88228285456453211702012-10-14T09:10:57.236-05:002012-10-14T09:10:57.236-05:00Marton,
No, it's a good question. The absence...Marton,<br />No, it's a good question. The absence of any of the modified Sgarbossa criteria (see the link to the abstract of my recent paper -- it is on the upper right of the blog) makes coronary occlusion very unlikely. Add that to the absence of chest pain or dyspnea, and it is more unlikely still. OK?<br />Steve SmithSteve Smithhttps://www.blogger.com/profile/08027289511840815536noreply@blogger.comtag:blogger.com,1999:blog-549949223388475481.post-32539103660406018022012-10-14T08:20:06.744-05:002012-10-14T08:20:06.744-05:00Dear Dr. Smith!
Case 2:
How do we know that the s...Dear Dr. Smith!<br /><br />Case 2:<br />How do we know that the syncope was the result of the aortic stenosis and not an arrhythmia or altered ventricular function due to a transient silent ischaemia (transient occlusion, unstable "angina")?<br />I mean OK, a severe aortic stenosis can cause symptoms like this and slightly elevated troponin levels, but I really don't want a patient like this that dies next day because of coronary occlusion...Is it a real danger, what do you think?<br />(Sorry, if my question is stupid or the answer is trivial...)<br /><br />Thank for your answer!<br /><br />Márton<br />med. student at Semmelweis University, HungaryAnonymoushttps://www.blogger.com/profile/08292096280571000937noreply@blogger.comtag:blogger.com,1999:blog-549949223388475481.post-45337515514418902752011-04-25T12:33:26.648-05:002011-04-25T12:33:26.648-05:00Here is a post that describes it:
http://hqmeded-e...Here is a post that describes it:<br />http://hqmeded-ecg.blogspot.com/2009/01/if-there-is-high-suspicion-for-ischemia.html<br /><br />Tom Bouthillet has done a great job of describing my ratio rule here: <br />http://ems12lead.com/tag/new-left-bundle-branch-block/Steve Smithhttps://www.blogger.com/profile/08027289511840815536noreply@blogger.comtag:blogger.com,1999:blog-549949223388475481.post-18727564739070442532011-04-25T11:59:10.754-05:002011-04-25T11:59:10.754-05:00Dr.Smith,
Do you have any post explaining how to d...Dr.Smith,<br />Do you have any post explaining how to diagnose MI in presence of LBBB?<br /><br />Regards<br />Dr.Bharath<br />www.clearmci.blogspot.comBharathhttps://www.blogger.com/profile/16790656317146003820noreply@blogger.comtag:blogger.com,1999:blog-549949223388475481.post-63544749269137665582010-03-12T14:04:43.596-06:002010-03-12T14:04:43.596-06:00Tom,
You're not misquoting me.
I've update...Tom,<br />You're not misquoting me.<br />I've updated the data (n was 13 and is now 34) and found that 0.20 is more sensitive without losing specificity.<br />SteveSteve Smithhttps://www.blogger.com/profile/08027289511840815536noreply@blogger.comtag:blogger.com,1999:blog-549949223388475481.post-79847831074334329552010-03-10T15:25:35.964-06:002010-03-10T15:25:35.964-06:00Dr. Smith -
For some reason I thought your modif...Dr. Smith - <br /><br />For some reason I thought your modified criterion was ST-elevation that is > 0.25 the QRS complex! <br /><br />I've been misquoting you. I'll make the necessary corrections on my blog.<br /><br />TomTom Bhttps://www.blogger.com/profile/18291404904437933272noreply@blogger.comtag:blogger.com,1999:blog-549949223388475481.post-60249491175148877292010-03-09T07:29:41.249-06:002010-03-09T07:29:41.249-06:001) LBBB may indeed be caused by coronary occlusion...1) LBBB may indeed be caused by coronary occlusion, especially large anterior STEMI that affects the conducting system. This may be reversed by reperfusion therapy. That is why NEW LBBB is more of an "indication" than old LBBB.<br />2) It is a misunderstanding that LBBB significantly obscures the EKG diagnosis of coronary occlusion. This conception is a leftover from the pre-imaging days when old MI (diagnosed with Q waves) was diagnosed by EKG, and LBBB does indeed obscure Q-waves. In the reperfusion era, we are looking for ST segment changes, not Q-waves. However, the notion that MI cannot be diagnosed in the presence of LBBB carried over to Acute MI. Additionally, the diagnosis of MI by biomarkers is confused with the diagnosis of complete coronary occlusion. In normal conduction, the diagnosis of MI as defined by biomarker elevation is very insensitive. There is a lot of evidence (that is not widely known) that the ECG in the presence of LBBB is nearly as sensitive for the diagnosis of occlusion as it is in normal conduction. See my chapter with references in Brady and Truwit: Critical Decisions in Emergency and Acute Care Electrocardiography.Steve Smithhttps://www.blogger.com/profile/08027289511840815536noreply@blogger.comtag:blogger.com,1999:blog-549949223388475481.post-31803168761482481972010-03-08T20:11:30.017-06:002010-03-08T20:11:30.017-06:00I think most people get the wrong impression from ...I think most people get the wrong impression from the common mantra that a LBBB with ischemic symptoms warrants a trip to the cath lab. Its not that ischemia or MI causes a LBBB, but rather that a LBBB makes the ability of detecting underlying ischemia more difficult. That is what makes the modified criteria mentioned above very helpful.Anonymousnoreply@blogger.com