tag:blogger.com,1999:blog-549949223388475481.post6241244360461367772..comments2024-03-19T02:33:29.499-05:00Comments on Dr. Smith's ECG Blog: How to measure ST Elevation at 60 milliseconds after the J-point in lead V3, relative to the PR SegmentUnknownnoreply@blogger.comBlogger8125tag:blogger.com,1999:blog-549949223388475481.post-11747225223658257472014-11-26T13:21:05.899-06:002014-11-26T13:21:05.899-06:00Thanks. I've spent quite a bit of time lookin...Thanks. I've spent quite a bit of time looking.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-549949223388475481.post-79118268588618621262014-11-25T15:18:04.899-06:002014-11-25T15:18:04.899-06:00The guidelines say to measure at the J-point relat...The guidelines say to measure at the J-point relative to the PQ jct. MacFarlane's article, on which the guidelines are based, (2004) (http://www.jecgonline.com/article/S0022-0736%2804%2900102-5/abstract?cc=y) used this (it is not in the methods, I had to write the author!). Sens. for MI was 46%, spec. 48% using their mm criteria. Outcomes were biomarker based, not angiographic. Measurements are very crude and unreliable estimates. Thrombolytic trials used various definitions but did not specify in the methods how to measure, so this was useless. The bottom line is, I believe, that the efficicay of reperfusion therapy was based more on a subjective ECG diagnosis of STEMI than on any critieria. And this is as it should be.<br />Steve SmithSteve Smithhttps://www.blogger.com/profile/08027289511840815536noreply@blogger.comtag:blogger.com,1999:blog-549949223388475481.post-49281911541859872722014-11-25T14:56:57.998-06:002014-11-25T14:56:57.998-06:00Dr. Smith,
I'm still confused on how to measu...Dr. Smith,<br /><br />I'm still confused on how to measure ST elevation. <br />I get how to measure it in the setting of the BER LAD formula.<br />What is the criteria otherwise. <br />I've heard the following reference points: <br />1) baseline: a) TP segment or b) PQ junction.<br />2) ST segment: a) at the J-point or b) 40 ms after the J-point. <br /><br />Thanks for any help. LawrenceAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-549949223388475481.post-51065882460088215822013-12-17T07:54:25.721-06:002013-12-17T07:54:25.721-06:00Thanks for your reply and the link to your article...Thanks for your reply and the link to your article.Michellehttps://www.blogger.com/profile/04194978210978394991noreply@blogger.comtag:blogger.com,1999:blog-549949223388475481.post-75827202911269585112013-12-16T08:28:13.373-06:002013-12-16T08:28:13.373-06:00Michelle,
You are exactly right about PR depressi...Michelle,<br /><br />You are exactly right about PR depression. The teachings on measurement of ST elevation are very variable throughout the decades. In the thrombolytic trials of the 1980s, the physicians did not have any instructions on how to measure STE. The ACC now says to measure at the J-point, relative to the PQ jct. (end of PR segment). PR depression lasts long enough that this should not distort the STE measurement. <br /><br />The measurement I have illustrated here is only for use in my BER LAD formula: we measured STE at J-point, and at 60 ms after the J-point, both relative to the PQ jct. (PR segment), and found that the best prediction came from this measurement at 60 ms after the J-point. If you're really interested, read this paper: http://download.journals.elsevierhealth.com/pdfs/journals/0196-0644/PIIS0196064412001606.pdf<br /><br />Steve SmithSteve Smithhttps://www.blogger.com/profile/08027289511840815536noreply@blogger.comtag:blogger.com,1999:blog-549949223388475481.post-5926390225389782912013-12-15T10:51:46.073-06:002013-12-15T10:51:46.073-06:00Thanks for posting this great diagram to help meas...Thanks for posting this great diagram to help measure ST segment elevation. My question is in regards to the reference point. I was always taught to measure the ST segment in reference to the TP segment either before or after the ST segment you are measuring. It is known that certain conditions such as pericarditis and atrial infaction can depress PR segments. In your example the PR segment is depressed by approximately 0.5mm. What are your thoughts about this?Michellehttps://www.blogger.com/profile/04194978210978394991noreply@blogger.comtag:blogger.com,1999:blog-549949223388475481.post-49904434801467349512013-12-09T15:21:24.963-06:002013-12-09T15:21:24.963-06:00Thanks. I knew that sounded wrong!Thanks. I knew that sounded wrong!Steve Smithhttps://www.blogger.com/profile/08027289511840815536noreply@blogger.comtag:blogger.com,1999:blog-549949223388475481.post-70798581993507159492013-12-09T12:28:14.837-06:002013-12-09T12:28:14.837-06:00PR segmentPR segmentAnonymoushttps://www.blogger.com/profile/09756132212488110543noreply@blogger.com