As an extension of this logic, reperfusion of the posterior wall should manifest on right precordial leads (which are opposite the posterior wall) as enlarged T-waves. Anterior MI is associated with more myocardial damage than inferior infarction; this damage affects LV function, a major determinant in prognostic outcome after acute MI. Terminal T-wave inversion becomes an upright T wave. There may be a hint of ST elevation in lead III with ST depression in I and aVL. However, isolated posterior MI, while less common (3-11% of infarcts2), is important to recognize as it is also an indication for reperfusion and can be missed by the ECG reader. Preference cookies are used to store user preferences to provide content that is customized and convenient for the users, like the language of the website or the location of the visitor. From ECGpedia. Inferior STEMI with posterior extension. ST-elevation myocardial infarction (STEMI) is suspected when a patient presents with persistent ST-segment elevation in 2 or more anatomically contiguous ECG leads in the context of a consistent clinical history. J Electrocardiol 1999;32: 275-8, Brady W, Erling B, Pollack M, et al. These cookies will be stored in your browser only with your consent. Posterior myocardial infarction (MI) represents 3.3 – 21% of all acute MIs and can be difficult to diagnose by the standard precordial leads. Select one: a. Sinus tachycardia, otherwise normal. By clicking “Accept”, you consent to the use of ALL the cookies. For echocardiographic classi-fication of Q-wave MI, the term posterior MI (PMI) has been replaced with ‘basal inferior’. The accuracy of four electrocardiographic criteria for diagnosing remote posterior myocardial infarction was assessed prospectively in 369 patients undergoing exercise treadmill testing with thallium scintigraphy. Posterior STEMI often occurs along with an inferior or lateral STEMI, but can also occur in isolation. Can lead to a cardiac aneurysm if not treated timely.. Proximal or distal occlusion of the LAD can be differentiated when looking at the ST elevation V1-V3 … The ECG demonstrates an acute inferior and lateral wall STEMI. Here is the Posterior #ECG we did in this case. Posterior wall infarct may occur in isolation in about 4% of cases. Additional ECG evidence of APMI is obtained by using posterior ECG leads V 8 and V 9(Figure 3). 7 Posterior ECG leads greatly improve sensitivity and specificity when identifying patients with isolated PMI. This site uses Akismet to reduce spam. The standard ECG lead placement cannot directly illustrate what is occurring in the posterior heart. In a codominant heart, a single or duplicated PDA is supplied by branches of both the RCA and LAD or LCx. Because no leads "look" at the posterior wall in the normal ECG, no leads show ST-elevation in case of a posterior wall infarction. On contrast some examples have v1, 2 and 3 cross out and are replaced by v7, 8 and 9. However, the lack of obvious ST elevation in this condition means that the diagnosis is often missed. Can someone please tell me the correct was to record a posterior ecg or are both ways acceptable? The ST-segment depressions in V1–V4 indicate extension of the STEMI to the posterior wall. He has a passion for ECG interpretation and medical education | ECG Library |. An ECG performed with the use of posterior leads revealed ST-segment elevation in leads V 7, V 8, and V 9, which was consistent with posterior-wall myocardial infarction. 7 Disclosure Statement. Your email address will not be published. [PMC. Note that the patient below is also suffering from a concurrent posterior wall infarction as eveidenced by ST depression in leads V1 and V2. It is mandatory to procure user consent prior to running these cookies on your website. The posterior wall is usually supplied of blood by the RCA. The ECG findings of an acute posterior wall MI include the following: ST segment depression (not elevation) in the septal and anterior precordial leads (V1-V4). The patient's ECG was not normal with the ST depression in V2-V5 (ok, maybe a little bit in V6). Look for deep (>2mm) and horizontal ST-segment depression in the anterior leads and large anterior R-waves (bigger than the S-wave in V2). Electrocardiographic (ECG) and vectorcardiographic (VCG) QRS voltage criteria have been analyzed in 26 patients with inferior and 17 with posterior myocardial infarction (MI) in comparison with left ventricular (LV) mass and global and regional wall motion as assessed by M-mode and two-dimensional (2D) echocardiography. Old Posterior wall MI. Stenting of the LAD was also performed for severe disease (80-90% stenosis). The previous image (depicting posterior infarction in V2) has been inverted. In order to recognize abnormalities that suggest ischemia or infarction, it is important to understand the components of a normal ECG. 2007; 15: 16-21. The OM1 was thought to be the artery responsible for the infarct and a stent was placed. There is also deep ST depression in the anterior leads (V1-3) with large R-waves in V2-3. Accuracy of 12 leads ECG for detection of posterior MI was thus calculated after confirmation by 15 leads ECG and was found to be 55% (Table 1). Posterior leads - ecg - posterior MI NEVER rely on Posterior Leads! Posterior infarction is confirmed by the presence of ST elevation and Q waves in the posterior leads (V7-9). Amongst these 10 patients had posterior MI (5.6%) con-firmed on 15 leads ECG. With acute posterior MI — these posterior leads will sometimes manifest ST elevation not seen on the standard 12 leads. The posterior wall of the LV is not directly viewed by any of the 12 leads on a standard ECG. Conduction abnormalities which may alert the physician to patients at risk include second degree AV block and complete heart block together with junctional escape beats. The prognosis of patients with anterior wall MI (AWMI) is significantly worse than patients with inferior wall MI. Isolated posterior MI is less common (3-11% of infarcts). ABC of clinical electrocardiography: Acute myocardial infarction-Part I. BMJ. Take conventional ECG There is sinus tachycardia, with deep ST depression in V1-V3. Posterior infarction is confirmed by the presence of ST elevation >0.5mm in leads V7-9. 73-2). Each group of leads on an ECG has anatomical significance. Out of these cookies, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities of the website. There is reciprocal depression in V1 and V2, indicating injury in the posterior wall. Which of the following diagnoses is the most appropriate one? There are several clues that suggest a left circumflex artery (LCA) occlusion. Posterior myocardial infarction: the dark side of the moon. (See Because the anterior wall is superior in its position in the chest, it is opposite the inferior/posterior wall, and can show ST depression when the inferior-posterior area has ST elevation. These cookies track visitors across websites and collect information to provide customized ads. V7 – Left posterior axillary line, in the same horizontal plane as V6. In case of sale of your personal information, you may opt out by using the link. Is supplied by blood by the LAD. Jump to navigation Jump to search. Electrocardiographic manifestations: acute posterior wall myocardial infarction. Posterior infarction accompanies 15-20% of STEMIs, usually occurring in the context of an inferior or lateral infarction. With the eye of faith there is perhaps also some early ST elevation in the inferior leads (lead III looks particularly abnormal). This ECG was originally published at: https://www.healio.com/cardiology/learn-the-heart/blogs/stemi-mi-ecg-pattern. When examining the ECG from a patient with a suspected posterior MI, it is important to remember that because the endocardial surface of the posterior wall faces the precordial leads, changes resulting from the infarction will be reversed on the ECG. The anteroseptal leads are directed from the anterior precordium towards the internal surface of the posterior myocardium. b. 2002; 324: 963-6. Posterior wall MI is most commonly associated with an inferior or lateral STEMI (occurring 15-20% percent of the time). Posterior extension of an inferior or lateral infarct implies a much larger area of myocardial damage, with an increased risk of left ventricular dysfunction and death. BMJ. A posterior ECG is done by simply adding three extra precordial leads wrapping around the left chest wall toward the back. However, isolated posterior MI, while less common (3-11% of infarcts 2), is important to recognize as it is also an indication for reperfusion and can be missed by the ECG reader. This represents an inferior-posterior STEMI. You gotta keep two ecgs and read it. Typically, leads V7 – V9 are needed to diagnose this entity. Posterior extension is suggested by: The same patient, with posterior leads recorded: In this ECG, posterior MI is suggested by the presence of: The ECG changes extend out as far as V4, which may reflect superior-medial misplacement of the V4 electrode from its usual position. You also have the option to opt-out of these cookies. In uncertain cases, a posterior ECG can be obtained by placing posterior leads V7, V8, and V9 below the patients left scapula along the same horizontal plane as V6. A R/S wave ratio greater than 1 in leads V1 or V2. Posterior infarction accompanies 15-20% of STEMIs, usually occurring in the context of an inferior or lateral infarction. The ECG shows ST elevation in the inferior leads (II, III, and aVF), and in the low lateral leads (V5 and V6). When the ecg is recorded how come in some of the examples above leads v4, 5 and 6 are crossed out and replaced by leads v7, 8 and 9. The ST depression and upright T waves in V2-3 suggest posterior MI. Swap leads v4, 5 and 6, and place them on the posterior aspect of the thorax as per diagram. #FOAMed Medical Education Resources by LITFL is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. Posterior MI is suggested by the following changes in V1-3: In patients presenting with ischaemic symptoms, horizontal ST depression in the anteroseptal leads (V1-3) should raise the suspicion of posterior MI. This website uses cookies to improve your experience while you navigate through the website. The … Background: Reperfusion after coronary occlusion (myocardial infarction, MI), as in Wellens' syndrome, is often represented on ECG as T-wave inversion in the leads overlying the affected myocardial wall(s). At least 0.5mm of ST elevation in one lead indicates posterior STEMI. e. Old Inferior MI. Acute anterior MI c. Acute inferior wall MI d. Sinus bradycardia with left anterior hemiblock and late transition e. Old anteroseptal MI. We use cookies on our website to give you the most relevant experience by remembering your preferences and repeat visits. Upright terminal portions of the T waves in V2-3. This occurs because these ECG leads will see the MI backwards; the leads are placed anteriorly, but the myocardial injury is posterior. emDOCs subscribes to the Free Open Access Meducation. [, Van Gorselen EO, Verheugt FW, Meursing BT, Oude Ophuis AJ. Leads V7-9 are placed on the posterior chest wall in the following positions (see diagram below): The degree of ST elevation seen in V7-9 is typically modest – note that only 0.5 mm of ST elevation is required to make the diagnosis of posterior MI!