tag:blogger.com,1999:blog-549949223388475481.post4817182613875215705..comments2024-03-28T14:02:08.119-05:00Comments on Dr. Smith's ECG Blog: A Pathognomonic ECG. What is it?Unknownnoreply@blogger.comBlogger9125tag:blogger.com,1999:blog-549949223388475481.post-6643814819058099932019-03-25T15:17:07.849-05:002019-03-25T15:17:07.849-05:00Hi Jerry. I believe our "comments" here ...Hi Jerry. I believe our "comments" here crossed — since your 3/22@11:18pm post did not appear on this blog until today (Steve has to go through all of these comments and approve them — which understandably TAKES TIME!) — but I had already (yesterday) altered my "Pearl #1" to say T wave rather than ST segment — MY THANKS to you for this excellent suggestion! Otherwise — what I LOVE about Steve's BLOG is that ALL of us learn from each other, as we ALL have different perspectives and experiences that complement each other! I've learned a LOT from you all! — :)ECG Interpretationhttps://www.blogger.com/profile/02309020028961384995noreply@blogger.comtag:blogger.com,1999:blog-549949223388475481.post-44514659214516376152019-03-24T18:26:58.378-05:002019-03-24T18:26:58.378-05:00My THANKS to Drs. Jerry Jones and K. Wang for thei...My THANKS to Drs. Jerry Jones and K. Wang for their comments. I like K Wang’s suggestion in terms of “thinking about a normal T wave being pushed out from a long ST segment”. JERRY — I just changed my Pearl #1 so that it now reads, “pure hypocalcemia does not affect the T wave”. I agree with you that this now reads clearer! The ST segment will often be flat — and in that sense, it seems “unaffected” — but K’s description “of the T wave being pushed out from a long ST segment” captures this best. THANKS again to you both! — :)ECG Interpretationhttps://www.blogger.com/profile/02309020028961384995noreply@blogger.comtag:blogger.com,1999:blog-549949223388475481.post-72693583377284477692019-03-22T23:18:31.304-05:002019-03-22T23:18:31.304-05:00Thank you for your insight Dr. Wang. However, I do...Thank you for your insight Dr. Wang. However, I don't think my query has yet been answered, although I DO understand - and accept - what you are saying. It's the "pushing out" and "pulling in" that is at issue here. Since this case is about hypocalcemia, let's limit our discussion to that. Ken's Pearl #1 asserts that hypocalcemia ALONE has NO EFFECT on the ST segment. That is simply not true. You yourself mention "a long ST segment" and "a short ST segment." Is this change in the duration of the ST segment not affected at all by the external Ca++ level and is it strictly due to decreases in Ik or Ip conductances? Or, does the [Ca++]o actually play a role in the duration of the ST segment? I think Ken's Pearl #1 would be spot on if "T wave" were substituted for "ST segment." I am certainly in complete agreement with you both that the T wave in hypocalcemia is NORMAL. The L-type Ca++ channels shut down in the early part of Phase 3 and add little (if any) to the T wave. But pure hypocalcemia alone would lengthen the ST segment because it isn't the EXTRACELLULAR Ca++ level that turns off the L-type Ca++ channels but the INTRACELLULAR Ca++ level. With hypocalcemia it takes longer to reach that intracellular threshold concentration - thus the prolonged Phase 2 (ST segment). Naturally-occurring deviations of the Ca++ level (hypo- or hypercalcemia) have no direct effect on the delayed K+ rectifier (Ik) current nor the inwardly rectifying K+ current (Ik1).<br /><br />So I maintain that hypocalcemia CAN and DOES affect the ST segment; BUT - in agreement with both of you - it presents with a prolonged (but otherwise unremarkable) ST segment terminated by a very NORMAL-appearing T wave.<br /><br />Dr. Wang - I've seen just about all your internet video postings and I've read your book "Atlas of Electrocardiography" (which I highly recommend). I have learned much from you. I'm still working my way through Ken Grauer's writings (he has been really prolific!) and am continuing to learn from him as well. Please accept my queries and observations in the spirit of learning and academia.<br /><br />Thank you,<br />Jerry W. Jones, MD<br /><br />P.S.- Steve, you're OK, too! ;-)Jerry W. Jones, MD FACEP FAAEMhttps://www.blogger.com/profile/10333187745825224414noreply@blogger.comtag:blogger.com,1999:blog-549949223388475481.post-69369896285981054522019-03-22T19:11:55.161-05:002019-03-22T19:11:55.161-05:00In hypo or hypercalcemia, don't think in terms...In hypo or hypercalcemia, don't think in terms of a long or short QT but in terms of normal T wave being pushed out from a long ST segment (of course the QT will end up long) or pulled in with a short ST segment. In long QT syndrome, the T wave starts right-a-way after the QRS with hardly any ST segment. If that T wave is "tented", add hyperkalemia as Dr. Ken Grauer did above.<br />K. Wang.Anonymoushttps://www.blogger.com/profile/04509940285330859355noreply@blogger.comtag:blogger.com,1999:blog-549949223388475481.post-39122296218355304592019-03-22T18:55:55.862-05:002019-03-22T18:55:55.862-05:00In hypokalemia it's actually a prominent U wav...In hypokalemia it's actually a prominent U wave resulting in a long QTU, not long QT. The prominent U wave may not be obvious in some leads while it is in other leads like in inferior leads. <br />K. Wang.Anonymoushttps://www.blogger.com/profile/04509940285330859355noreply@blogger.comtag:blogger.com,1999:blog-549949223388475481.post-28099880915721997892019-03-22T17:24:32.277-05:002019-03-22T17:24:32.277-05:00Because it is a long flat ST segment. HypoK does ...Because it is a long flat ST segment. HypoK does not have such a flat ST segment. Search for hypokalemia on this blog to see many examples.Steve Smithhttps://www.blogger.com/profile/08027289511840815536noreply@blogger.comtag:blogger.com,1999:blog-549949223388475481.post-72892287928493983852019-03-21T15:35:25.012-05:002019-03-21T15:35:25.012-05:00Ken...
Your Pearl #1 has me a bit confused: "...Ken...<br /><br />Your Pearl #1 has me a bit confused: "PEARL #1: In theory — pure hypocalcemia does not affect the ST segment!" Did you mean "T wave?"Jerry W. Jones, MD FACEP FAAEMhttps://www.blogger.com/profile/10333187745825224414noreply@blogger.comtag:blogger.com,1999:blog-549949223388475481.post-54988089857370868132019-03-21T01:32:24.573-05:002019-03-21T01:32:24.573-05:00Why is this prolonged qt(or qu interval) not sugg...Why is this prolonged qt(or qu interval) not suggestive of Hypokalemia ?Subhasish Singh herehttps://www.blogger.com/profile/18022600313880536118noreply@blogger.comtag:blogger.com,1999:blog-549949223388475481.post-60279301160304922302019-03-19T19:54:07.099-05:002019-03-19T19:54:07.099-05:00It is believed that the reason why long QT interva...It is believed that the reason why long QT interval due to hypocalcwmia is not predisposed to torsades de pointes is because the QT is prolonged homogeneously in the LV in hypocalcemia while, in long QT syndrome, the QT is prolonged inhomogeneously in the LV causing potential gradient from one area of LV to the next, setting up for torsades de pointes. Anonymoushttps://www.blogger.com/profile/04509940285330859355noreply@blogger.com