Materials appearing in this book prepared by individuals as part of their official duties as u. Jason mitchell, pgy2 july 15, 2010 context cp and st elevation common ed presentation correct ecg interpretation impacts management decisions and patient outcome certain patients with cp and st elevation require rapid intervention via thombolysis or pci misdiagnosis potentially harmful context 1996 accaha class i recommendation for thrombolysis st elevation. Okeefe, james h hammill, stephen c freed, mark s pogwidz, steven m. St elevation of less than 1 mm is designated as a female pattern. Since the majority of men have st elevation of 1 mm or more in precordial leads, it is a normal finding, not a normal variant, and is designated as a male pattern. Ecg terminology and diagnostic criteria often vary from book to book and from one teacher to another. The 12 lead ecg in st elevation myocardial infarction. In chous electrocardiography in clinical practice sixth edition, 2008. Concave st segment elevations are extremely common in any population.
The st segment is the flat, isoelectric section of the ecg between the end of the s wave the j point and the beginning of the t wave. St segment elevation seen in early hours of infarction last from several hours to several days reciprocal changes. Differentiation of j point elevation andor st segment elevation. Left bundle branch block diagnosing myocardial infarction sgarbossa criteria left main coronary artery occlusion st elevation in avr left posterior fascicular block. Widespread st depression v36, i, ii, iii, avf this patient had a severe ostial lad thrombus that was close to the left main. The st segment litfl medical blog ecg library basics. This ecg is reproduced from dr smiths ecg blog head on motor vehicle collision. Methodological ecg interpretation the ecg must always be interpreted systematically.
Concordant st elevation 1mm in leads with a positive qrs complex score 5 concordant st depression 1 mm in v1v3 score 3 excessively discordant st elevation 5 mm in leads with a negative qrs complex score 2. Interval between ventricular depolarization and repolarization. The interpretation algorithm presented below is easy to follow and it. Accaha guidelines for the management of patients with st. Identify ecg changes related to hypertrophy, bundle branch blocks.
Francis morris, abc of clinical electrophysiology, bmj book, isbn 0 7279 1536 3. In this tutorial an attempt has been made to conform to standardized terminology and criteria, although new diagnostic concepts derived from the recent ecg. Ecg criteria for stemi are not used in the presence of left bundle branch block lbbb or left ventricular hypertrophy lvh because these conditions cause secondary stt changes which may mask or simulate ischemic stt changes. General introduction to st, t, and u wave abnormalities. Acute myocardial infarction preprinted order sheet.
The st segment represents the interval between ventricular depolarization and repolarization. Failure to perform a systematic interpretation of the ecg may be detrimental. Stsegment elevation on ecg is crucial for emergent reperfusion. Benign st segment elevation is very common in the population, particularly in the precordial leads v2v6. Wide q waves longer than 35 ms and prolonged qt interval. Ecgs for the emergency physician 1 by amal mattu and william brady. There is no definite way to rule out myocardial ischemia by judging the appearance of the st segment, which is why north american and european guidelines assert that the appearance of the. The most important cause of st segment abnormality elevation or depression is myocardial ischaemia or infarction. E books, ee library passwords, ezproxy databases, ovid, hinari, springer, jstor, nejm, accessscience, sage, ieee, sciencedirect. Pdf differential diagnosis of st segment elevation on ecg. Guidelines acute myocardial infarction stsegment elevation acute coronary syndromes. An acute stelevation myocardial infarction stemi is an event in which. In this tutorial an attempt has been made to conform to standardized terminology and criteria, although new diagnostic concepts derived from the recent ecg literature have been included in some of the sections.
St elevation electrocardiography myocardial infarction. The diagnosis of stemi should be made by a 12lead ecg. Most patients presenting with nstemi ultimately develop a nqmi on the ecg. Old anterior wall myocardial infarction mi ecg anterior wall st elevation mi with rbbb ecg example 2 anterior wall st elevation mi with rbbb ecg example 1 anterior wall st elevation mi ecg. The baseline is either the pr interval or the tp interval. Steve smith on ecgs emcrit pediatric ecg interpretation emin5 books. This book is distributed under the terms of the creative commons attribution. Due to slight differences in methodology, the final rule uses 0.
Generally, ecg changes do not correspond to a specific coronary territory and usually lack. During right ventricular pacing the ecg also shows left bundle brach. An acute stelevation myocardial infarction stemi is an event in which transmural myocardial ischemia results in myocardial injury or necrosis. The third ecg, titled 12lead 5, shows a maturing of the st segment elevation. When a stemi is suspected, a 12lead ecg must be acquired and. Ecg reference sites and books the best of the rest.
Stelevation myocardial infarction stemi is a clinical syndrome defined by characteristic symptoms of myocardial ischemia in association with persistent electrocardiographic st elevation ste and subsequent release of biomarkers of myocardial necrosis. In patients with acute stemi the ecg evolves through a. Anterior wall st segment elevation myocardial infarction. Ecg in stemi definition of stemi new st elevation at the j point in two contiguous leads of 0. If uncertainty about the diagnosis exists, repetitive ecg recordings, together with additional information from echocardiography and laboratory testing, can be included as long as it does not cause any delay in. Stsegment elevation in conditions other than acute. The ecg criteria book will be a nice supplement to the main text. Duration pdf available in singapore medical journal 521. Diagnosis of stelevation myocardial infarction in the presence of left bundle branch block with the stelevation to swave ratio in a modified sgarbossa rule there are differences between previous posts and the findings in this paper. Bousfield describes the spontaneous changes in the ecg during. Even though there is some significant artifact, we can see that the st segment in v1 is coved upward, and the st segment in v2 is flat. An st elevation is considered significant if the vertical distance inside the ecg trace and the baseline at a point 0.
Resident will be able to describe and recognize the characteristics of common ecg diagnoses. Up to 90% in some ageranges of healthy men and women display concave stsegment elevations in v2v6 this is called malefemale pattern. Acute myocardial infarction st elevation stemi statpearls ncbi. It is a nice size for students to take on clinical rotations. The deeper the s wave, the greater the stsegment elevation a. Sponsored supplements branded books journals career network.