Sections View Full Chapter Figures Tables Videos Full Chapter Figures Tables Videos Supplementary Content +++ ECG Findings ++ ST-segment elevation in the precordial leads (V1-V6). Q-wave formation in the precordial leads (V1-V6). Reciprocal ST-segment depression in the inferior leads (II, III, aVF). V1-V2: Septal injury. V3-V4: Anterior injury. V5-V6, I, and aVL: Anterolateral injury. Lateral injury may involve leads I and aVL only, and this is sometimes referred to as “high lateral” injury. +++ Pearls ++ Anterior STEMI results from occlusion of the left anterior descending (LAD) artery. Anterior STEMI due to LAD artery occlusion has the worst prognosis of all STEMI locations. This is due to the large territory supplied by the LAD. The reciprocal changes seen in the inferior leads (II, III, and aVF) are proportional to the magnitude of the ST elevations in I and aVL, and hence may be absent if the anterior STEMI does not involve the high lateral leads. A “wrap around LAD” occlusion can produce ST elevations in not only the anterior precordial leads but also the inferior and lateral leads. This type of STEMI can easily be mistaken for pericarditis or early repolarization because of the ST elevations in multiple vascular territories and the absence of reciprocal ST depression. ++ FIGURE 23.2A Acute Anteroseptal Myocardial Infarction. (ECG contributor: James V. Ritchie, MD.) Graphic Jump LocationView Full Size|Favorite Figure|Download Slide (.ppt) ++ FIGURE 23.2B Pathologic ST-segment elevation beyond 1 mm (double arrow) with pathologic Q waves (arrow) in lead V3. The ST segment demonstrates a convex upward, or “tombstone,” morphology. Graphic Jump LocationView Full Size|Favorite Figure|Download Slide (.ppt) GET ACCESS TO THIS RESOURCE Sign In Username Error: Please enter User Name Password Error: Please enter Password Forgot Username? Forgot Password? Sign in via OpenAthens Sign in via Shibboleth Get Free Access Through Your Institution Contact your institution's library to ask if they subscribe to McGraw-Hill Medical Products. Access My Subscription GET ACCESS TO THIS RESOURCE Subscription Options Pay Per View Timed Access to all of AccessEmergency Medicine 24 Hour $34.95 (USD) Buy Now 48 Hour $54.95 (USD) Buy Now Best Value AccessEmergency Medicine Full Site: One-Year Individual Subscription $595 USD Buy Now View All Subscription Options