New Online Resource for ECG Interpretation

Stephen W. Smith, MD is the creator of “Dr. Smith’s ECG Blog,” an online ECG resource. Dr. Smith is a Faculty Emergency Physician at Hennepin County Medical Center and Associate Professor of Emergency Medicine at University of Minnesota School of Medicine in Minneapolis, Minnesota. What is the purpose of this website? When and why was it launched? The purpose is to educate on ECG interpretation, with a special focus on the recognition of subtle ST elevation due to coronary occlusion, and differentiation from pseudoinfarction patterns. The website was launched in the fall of 2008. I had previously written many chapters, a book, and a book section, but did not like that my work was copyrighted and difficult to reprint. The blog allows me to publish without difficulty and use the material for any purpose that I want. What information do you have included on the website? How often do you update the site? The site includes case studies with ECGs. Most are from my institution (Hennepin County Medical Center), where I am a faculty emergency physician. Some are sent to me from interested parties across the nation. I update it whenever I have time. I have a huge stack of interesting ECGs that I would like to add to the blog, but I am currently very busy serving as a Cardiology Decision Editor for Academic Emergency Medicine, Cardiology Reviewer for the Annals of Emergency Medicine, as well as teaching and handling administration in our department. I am also working on my own research (most of which is on the ECG in acute MI), and writing book chapters and sections, most recently the section on “Acute Coronary Syndromes” in Critical Decisions in Emergency and Acute Care Electrocardiography (William Brady and J.D. Truwit, editors; Blackwell Publishing). In addition, I previously published my own book: The ECG in Acute MI (Lippincott Williams & Wilkins) in 2002. This book was also translated into Chinese. What are some of the more interesting ECGs you have included? Some of the topics I have discussed on the website include: • Acute anterior MI or benign early repolarization? • ST elevation on prehospital ECG that is gone upon arrival to the ED • ST elevation due to GI bleed and atrial fibrillation with RVR, which resolves after cardioversion • Pure isolated posterior STEMI • Bundle branch block with acute STEMI • Circumflex occlusion may be subtle or invisible on the initial 12-lead ECG • Hyperacute T waves • Acute STEMI or previous MI with persistent ST elevation (“LV aneurysm”)? Have there been any ECGs in general that you felt were particularly difficult to diagnose or understand? Which ones? Differentiation of inferolateral MI from pericarditis is very difficult, unless there is reciprocal ST depression in aVL. If this reciprocal ST depression is present, it is highly predictive of the diagnosis of STEMI. However, localized pericarditis is the one unusual exception; most pericarditis is diffuse and has no reciprocal ST depression. Anterior STEMI often looks very much like early repolarization. I am finishing a comparative study of the two entities and have found that the most discriminating characteristics are: mean R wave amplitude from V2-V4, QTc, mean ST elevation from V2-V4. I am now investigating the “degree of upward concavity” in V2-V4. This is measured as follows: draw a line from the J point to the convex inflection of the T-wave (line B); draw a line perpendicular down to the upwardly concave ST segment (line A). I suspect that the ratio of B/A will be larger for early repolarization than anterior STEMI, and that this will help to discriminate the two entities. What sort of feedback have you received about your website? Who do you find most often visits your website? Although I do not have data on who visits the site, I do receive a lot of comments from physicians outside the U.S. and from paramedics. What suggestions can you offer to those who are trying to learn about ECGs? What are some of the important lessons you’ve learned over the years? Practice, practice, and study, study. Read good references. I highly recommend the two texts referenced above and, of course, the ECG blog. Is there anything else you’d like to add? If you are a physician or paramedic who treats patients with chest pain, you must be an expert in the interpretation of the 12-lead ECG, as well as in the recognition of ischemic patterns and in differentiation from the look-alikes. It takes an enormous amount of practice and study. For more information, please visit: www.hqmeded.com/blogs/page1/page1.html