tag:blogger.com,1999:blog-549949223388475481.post8755528776157876352..comments2024-03-28T14:02:08.119-05:00Comments on Dr. Smith's ECG Blog: Cardiac Arrest, hypotension, tachycardiaUnknownnoreply@blogger.comBlogger2125tag:blogger.com,1999:blog-549949223388475481.post-67340405306135228552010-12-24T05:35:28.843-06:002010-12-24T05:35:28.843-06:00Thank you for your input, Hatim. You may very wel...Thank you for your input, Hatim. You may very well be correct. <br /><br />I should clarify that I also do not find the ECG diagnostic of posterior STEMI, but there are features that argue for it. There appears to be a posterior fascicular block, and this will eliminate the Q-wave of a lateral MI and may also eliminate the increased precordial R-wave of posterior STEMI. Subendocardial ischemia usually, not always, extends to V5 and V6. STE in aVR seldom has any independent value, in spite of the many articles featuring it: it is really the same as ST depression in the lead (-) aVR, which is at 30 degrees, between I and II. The best measure is ST axis, which in this case is -90, or straight up, corresponding to an isoelectric ST in I, and negative in (-)aVR, II, aVF, III. I agree with you that an ST axis straight up is usually subendocardial ischemia (or STEMI at the base of the heart). And subendocardial ischemia is likely with high demand (hypotension and tachycardia). So the ECG is inconclusive. We know from the surgical findings that it was a lateral transmural completed infarct, but know little else about the coronary anatomy.Steve Smithhttps://www.blogger.com/profile/08027289511840815536noreply@blogger.comtag:blogger.com,1999:blog-549949223388475481.post-26282733195796697532010-12-22T19:15:19.194-06:002010-12-22T19:15:19.194-06:00Fascinating case! Thank you! However, allow me to ...Fascinating case! Thank you! However, allow me to argue against this ECG suggesting a posterior MI. The hallmark of an acute posterior infarct is ST depression in V1-V2 (the equivalent of ST elevation in other leads). Also, there are no tall R waves in V1-V2 to along with that. This patient's event was likely that time she started feeling unwell which was 36 hrs ago. I would expect a tall R wave in those leads, the equivalent of a Q wave elsewhere. <br />This patient, no doubt, has ST elevation in the lateral leads. The changes in the inferior leads could very well be reciprocal. However, the ECG is very suggestive of diffuse sub-endocardial ischemia from hypotension, the cardiac arrest and the catecholamines she was resuscitated with. ST elevation in aVR is classical for this phenomenon and we see it clearly in this patient.Hatim Al Lawatinoreply@blogger.com