tag:blogger.com,1999:blog-549949223388475481.post4128545177520309352..comments2024-03-26T22:42:04.176-05:00Comments on Dr. Smith's ECG Blog: A patient with a "seizure" and a completely "normal" ECGUnknownnoreply@blogger.comBlogger5125tag:blogger.com,1999:blog-549949223388475481.post-49939674789217805362018-04-06T08:59:34.630-05:002018-04-06T08:59:34.630-05:00That is true, except the idea about hypothermia is...That is true, except the idea about hypothermia is not something I am aware of.Steve Smithhttps://www.blogger.com/profile/08027289511840815536noreply@blogger.comtag:blogger.com,1999:blog-549949223388475481.post-32238277031912341982018-04-06T05:05:03.835-05:002018-04-06T05:05:03.835-05:00Dr Smith,
I have heard that only hypocalcemia and ...Dr Smith,<br />I have heard that only hypocalcemia and hypothermia prolongs the QT interval by prolonging the ST segments. While long QT of other causes (i.e hypoK, drugs, ischaemia) prolongs the QT by prolonging the T wave/U wave.<br />What do you think?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-549949223388475481.post-1439765947060720542018-03-12T09:22:41.779-05:002018-03-12T09:22:41.779-05:00It is the longest QT of the 12 leads, usually II, ...It is the longest QT of the 12 leads, usually II, V2, or V5Steve Smithhttps://www.blogger.com/profile/08027289511840815536noreply@blogger.comtag:blogger.com,1999:blog-549949223388475481.post-87980994870541328212018-03-10T04:57:18.185-06:002018-03-10T04:57:18.185-06:00Nice case! Lots of artifact on the initial ECG! — ...Nice case! Lots of artifact on the initial ECG! — but we see complexes reasonably well in leads V4,V5,V6 — and what struck me is a rounder (broader) than-usual T wave. As per Dr. Smith — the QTc appears to be somewhat long. The “eyeball estimation method” — shows the QT in V5 to be clearly more than half the R-R interval in this lead. Using calipers — I measured the actual QT interval in lead V5 = 440 msec. At a heart rate of 70-75/minute — this corrects to a value clearly above the normal range (ie, >450msec). My favorite “List” are the causes of a long QTc = i) Drugs; ii) Lytes (ie, low K+/Mg++/Ca++); and/or iii) CNS catastrophes. Clearly, other things (ie, acute ischemia/infarction, BBB) can lengthen the QTc — but these other factors aren’t operative in this case. While true that this patient just had a seizure that might alter the QTc — the beauty of this list (in my experience) — is that it prompts the interpreter to consider all 3 entities likely to produce QTc lengthening as the sole ECG abnormality — which in this case should prompt checking serum electrolytes. THANKS to Dr. Smith for presenting this illustration of how an ECG may help in a noncardiac disorder!ECG Interpretationhttps://www.blogger.com/profile/02309020028961384995noreply@blogger.comtag:blogger.com,1999:blog-549949223388475481.post-68429883414146201012018-03-09T14:51:38.851-06:002018-03-09T14:51:38.851-06:00Hello, in which lead should QT be measured, II, V5...Hello, in which lead should QT be measured, II, V5, V6? Or in the leads with the longest QT?<br /><br />Anonymousnoreply@blogger.com