tag:blogger.com,1999:blog-549949223388475481.post3130959079872970289..comments2024-03-28T14:02:08.119-05:00Comments on Dr. Smith's ECG Blog: Acute Chest Pain: Computer reads "Nonspecific ST-T abnormalities"Unknownnoreply@blogger.comBlogger5125tag:blogger.com,1999:blog-549949223388475481.post-58425047322567921262016-12-12T05:53:30.991-06:002016-12-12T05:53:30.991-06:00Exactly right on all counts, Jerry. Thanks!
Steve...Exactly right on all counts, Jerry. Thanks!<br />SteveSteve Smithhttps://www.blogger.com/profile/08027289511840815536noreply@blogger.comtag:blogger.com,1999:blog-549949223388475481.post-7716225961032007932016-12-12T05:51:47.113-06:002016-12-12T05:51:47.113-06:00David, criteria are meant to ensure high specifici...David, criteria are meant to ensure high specificity for interpreters who are uncertain. A full 25% of acute 100% coronary occlusions do not meet STEMI criteria. Thrombolysis is indicated here.<br />Steve SmithSteve Smithhttps://www.blogger.com/profile/08027289511840815536noreply@blogger.comtag:blogger.com,1999:blog-549949223388475481.post-67266816083985999422016-12-11T08:06:43.403-06:002016-12-11T08:06:43.403-06:00Steve...
The first ECG is is the kind of ECG that...Steve...<br /><br />The first ECG is is the kind of ECG that I remember most when giving expert testimony. As Dr. Grauer stated, this is not all that subtle to someone who is an expert based on years of interpreting thousands of ECGs, but it is dangerously subtle to a much less experienced emergency or critical care physician who is probably overworked and sleep-deprived at 4 am.<br /><br />Three things in the first ECG grabbed my attention immediately and instantaneously: the wide T waves in the precordial leads, the straightening of the ST segment into the T wave in aVL (most evident in the second complex in that lead) and the subtle planar ST depression in II and aVF with distinct ST-T junctions.<br /><br />I teach advanced electrocardiography and I find so many physicians who only recognize hyperacute T waves when they are very tall and peaked (i.e., when they look most like hyperkalemic T's). WIDE hyperacute T waves are more frequent and (I feel) more typical (though some are tall and peaked).<br /><br />Also, a straight, upward sloping ST segment that continues to the apex of the T wave - especially in the setting of a patient with credible ACS symptoms - should always, ALWAYS be a red flag! That is an ST segment that is transitioning from upward concavity to upward convexity. I also find that many of my students tend to overlook Lead aVL, especially because the QRS is often very small, being perpendicular to Lead II and the majority of mean QRS axes in the frontal plane. Sometimes you just have to use a magnifying lens to see that the ST segment begins with a J point elevation that is at times =/> 50% the height of the R wave. During my residency I trained under a number of cardiologists, all of whom impressed on me that Lead aVL alone was probably the source of more malpractice litigation than one could imagine.<br /><br />The planar ST depression in Leads II and aVF with the distinct ST-T junction also caught my eye immediately. The ST depression is very, very subtle but I wouldn't need it to strongly suspect a reciprocal change. A flat ST segment and the distinctive take-off of the T wave would have been enough.<br /><br />This is an excellent teaching case!<br /><br />Thanks.Jerry W. Jones, MD FACEPhttps://www.medicusofhouston.comnoreply@blogger.comtag:blogger.com,1999:blog-549949223388475481.post-7582630157902149752016-12-10T18:34:58.040-06:002016-12-10T18:34:58.040-06:00This was a very concerning story and ECG series fr...This was a very concerning story and ECG series from the start. What is most interesting / worrying for me is that my hospital is 2,000km from a cath lab and he did not meet our thrombolysable criteria. Who reading this would have thrombolysed him at this stage? Clearly, he would have almost certainly gone on to widespread ST elevation, which would have been 'thrombolysable', but more damage would have been done by then.Davidhttps://www.blogger.com/profile/13424553740799106863noreply@blogger.comtag:blogger.com,1999:blog-549949223388475481.post-36981694042409383952016-12-10T15:48:57.070-06:002016-12-10T15:48:57.070-06:00Unless one is a true expert interpreter (ie, this ...Unless one is a true expert interpreter (ie, this means you’ve interpreted at least several hundred thousand tracings over MANY years, and require no more than 3-5 seconds to recognize 90-95% of the abnormalities on most tracings) — you should NOT look at the computerized report until AFTER you have made you own INDEPENDENT interpretation of an ECG. The reason is simple — you might see “nonspecific ST-T abnormalities” for a tracing like this, and thus be dissuaded into thinking there is a possibility of something non-acute. There should be NO DOUBT in the context of a 60yo man with new-onset severe chest pain that this 1st ECG represents acute LAD occlusion until proven otherwise. Significant findings (as per Dr. Smith) include: i) ST elevation in the chest leads beginning in lead V2 through to V5; ii) most definitely more peaked-than-they-should-be T waves especially in V3,V4 (but also in V2,V5); iii) subtle-but-real ST elevation with slight T inversion in aVL; and iv) subtle-but-real reciprocal changes in the inferior leads (with biphasic T in lead III). The inferior Q waves may or may not be related to the acute event … but we KNOW that “the action” is in anterior chest leads.<br /><br />Overall, I like computerized ECG interpretations. They literally tripled my speed for interpretation back in the days when I was reading large piles of tracings for all of our providers. But that’s because I know exactly what the computer can and cannot do. For anyone who is not a true expert (definition above in my 1st sentence) — you should use the computer as a “check” to ONLY be looked at AFTER you have already made your own independent interpretation of the ECG. The computerized report might then suggest something you didn’t see. But if the computerized report says, “non-specific changes” for a tracing like this — Do NOT believe it, because the computer is wrong … THANKS to Dr. Smith for this highly illustrative post!ECG Interpretationhttps://www.blogger.com/profile/02309020028961384995noreply@blogger.com