Critical Decisions in Emergency and Acute Care Electrocardiography E-Book

• Herausgeber: John Wiley & Sons
• Kategorie: Fachliteratur
• Sprache: Englisch

Seitenzahl: 1236

Veröffentlichungsjahr: 2011

Beschreibung

This scenario-based text provides answers to urgent and emergent questions in acute, emergency, and critical care situations focusing on the electrocardiogram in patient care management. The text is arranged in traditional topics areas such as ACS, dysrhythmia, etc yet each chapter is essentially a question with several cases illustrating the clinical dilemma - the chapter itself is a specific answer to the question. This is a unique format among textbooks with an ECG focus. The clinical scenarios cover the issues involved in detecting and managing major cardiovascular conditions. Focused, structured discussion then solves these problems in a clinically relevant, rapid, and easy to read fashion. This novel approach to ECG instruction is ideal for practicing critical care and emergency physicians, specialist nurses, cardiologists, as well as students and trainees with a special interest in the ECG.

Leseprobe

Contents

Section Editors

Contributors

Preface

Foreword 1

Foreword 2

Part 1 The ECG in Clinical Practice

1 What are the clinical applications of the ECG in emergency and critical care?

Case presentations

Clinical applications of the ECG

Case conclusions

2 What are the indications for the ECG in the pediatric emergency department?

Case presentations

Clinical indication for the ECG in pediatric emergency and critical care medicine

Case conclusions

3 What are the limitations of the ECG in clinical practice?

Case presentations

Limitations of the ECG

Case conclusions

4 Is the ECG indicated in stable, non-cardiac patients admitted to the hospital?

Case presentations

The ED ECG in the hospital admission process

Value of electrocardiography

Case conclusions

5 What is the use of the ECG in preoperative assessment and cardiovascular risk stratification?

Case presentations

The ECG in preoperative evaluation

Who needs an ECG prior to surgery?

What does the ECG indicate about cardiovascular risk?

What does the ECG indicate about the presence of structural heart disease?

What does the ECG indicate about the presence of ischemic heart disease?

What does the ECG indicate about the presence of conduction system abnormalities?

What does the ECG indicate about risk of intra-operative arrhythmias?

Case conclusions

6 Which patients benefit from continuous electrocardiographic monitoring during hospitalization?

Case presentations

Continuous electrocardiographic monitoring for the admitted patient

Basic set-up and monitoring of telemetry

Role of telemetry in clinical practice

Ischemic syndromes

Arrhythmia

Syncope

Heart failure

Other indications

Case conclusions

Part 2 The ECG in Cardinal Presentations

7 How should the ECG be used in the syncope patient?

Case presentations

The ECG in the patient with syncope

Cardiac etiologies of syncope

Structural cardiac disease

Case conclusions

8 How should the ECG be used in the chest pain patient?

Case presentations

The ECG in the chest pain patient

The ECG in suspected ACS presentations

ECG evaluation in specific non-ACS diagnoses

Case conclusions

9 How should the ECG be used in the dyspneic patient?

Case presentations

The ECG in the patient with dyspnea

Cardiac causes of dyspnea

Pulmonary causes of dyspnea

Other non-cardiac causes of dyspnea

Case conclusions

10 How should the ECG be used in the patient with altered mentation?

Case presentations

The ECG in the patient with altered mental status

The ECG and coma

The ECG and primary CNS disorders

The ECG in toxic delirium

Case conclusions

11 How should the ECG be used in the patient during and following cardiac arrest?

Case presentations

The ECG in the patient with cardiac arrest

ECG rhythms seen in cardiac arrest

Initial management of ECG rhythms

Asystole/pulseless electrical activity

How should the ECG be used following cardiac arrest?

Case conclusions

12 What is the impact/proper role of the ECG in the undifferentiated cardiorespiratory failure patient?

Case presentations

The ECG in undifferentiated cardiorespiratory failure

The differential diagnosis of cardiorespiratory failure

Electrocardiographic features of syndromes contributing to cardiorespiratory failure

Case conclusions

Part 3 The ECG in ACS

13 What is the role of the ECG in ACS?

Case presentations

The role of the ECG in the ACS patient

ST elevation myocardial infarction

ST segment elevation

Evolution of STEMI

Non-ST elevation MI and unstable angina

Conclusion

Case conclusions

14 What pseudoinfarction patterns mimic ST elevation myocardial infarction?

Case presentations

Mimics of acute myocardial infarction

Pseudo-infarction patterns

Serial ECGs/echocardiography/ angiography

Normal variant or benign early repolarization

Electrocardiographic features of BER, in contrast to STEMI

Pericarditis/myocarditis

Stress cardiomyopathy

Prior myocardial infarction/ left ventricular aneurysm

Brugada syndrome

Hyperkalemia

Pulmonary embolism

General strategies for differentiating pseudo-infarction from STEMI

Case conclusions

15 What ECG changes might myocardial ischemia cause other than ST segment elevation or Q waves and what are the differential diagnoses of these changes?

Case presentations

General discussion of ST and T wave, and U wave abnormalities in ischemia

T wave abnormalities

Differential diagnosis of T wave inversion

Conditions with an abnormal QRS resulting in secondary T inversions

T wave flattening

U wave

ST segment depression

ST depression due to subendocardial ischemia

Anterior ST depression representing posterior MI

Differential diagnosis of ST segment depression

Case conclusions

16 What is a hyperacute T Wave?

Case presentations

The hyperacute T wave

Conclusion

Case conclusions

17 What is the significance of Q waves?

Case presentations

The significance of Q waves

Anatomic correlates of infarction

Differential diagnosis

Case conclusions

18 What are the ECG indications for additional electrocardiographic leads (including electrocardiographic body-surface mapping) in chest pain patients?

Case presentations

ECG indications for additional electrocardiographic leads

Indications for additional ECG leads

Posterior precordial leads and posterior wall infarction

12-Lead ECG findings in PMI

Posterior lead orientation and diagnostic criterion

Right-sided ECG and right ventricular infarction

Right-sided lead orientation and diagnostic criterion

Electrocardiographic body-surface mapping

Conclusion

Case conclusions

19 What further diagnostic adjuncts to the standard 12-lead ECG may help to diagnose ACS?

Case presentations

Adjunctive modalities in the diagnosis of ACS

Previous ECG comparison and serial ECG monitoring

Cardiac biomarkers

ECG adjuncts in left bundle branch block

Additional ECG leads

Non-invasive imaging

Echocardiography

Myocardial perfusion imaging

Magnetic resonance imaging and computed tomography

Coronary angiography

Summary

Case conclusions

20 Is serial electrocardiography (serial ECGs and ST segment monitoring) of value in the ECG diagnosis of ACS?

Case presentations

The use of serial ECGs

Continuous ST segment monitoring

Assessment of coronary artery patency

Conclusion

Case conclusions

21 What QRS complex abnormalities result in ST segment elevation that may mimic or obscure AMI?

Case presentations

Conditions that obscure MI because of an abnormal QRS

Case conclusions

22 What are the electrocardiographically silent areas of the heart?

Case presentations

The electrocardiographically silent areas of the heart

Normal and non-specific ECGs in ACS

Lateral myocardial infarction

Posterior myocardial infarction

Right ventricular myocardial infarction

Subtle inferior or anterior MI

Conclusion

Case conclusions

23 What is the value of the prehospital acquired 12-lead ECG?

Case presentations

The value of the prehospital 12-lead electrocardiogram

Impact of prehospital 12-lead electrocardiogram on hospital-based reperfusion

Utility of prehospital ECG on the diagnosis of unstable angina and non ST elevation MI

The impact of the prehospital 12-lead electrocardiogram on prehospital care

Case conclusions

24 What are the electrocardiographic indications for reperfusion therapy?

Case presentations

The electrocardiographic indications for reperfusion (fibrinolysis or percutaneous coronary intervention) in presumed acute myocardial infarction

ST segment elevation

Magnitude of ST segment elevation

Bundle branch block

ST segment depression

Acuteness – when is it too late for reperfusion?

Case conclusions

25 What are the ECG manifestations of reperfusion and reocclusion?

Case presentations

The electrocardiographic manifestations of reperfusion and reocclusion

ECG manifestations of reperfusion

ST segments

T waves

Reperfusion arrhythmias

ECG manifestations of reocclusion

Conclusion

Case conclusions

26 Does localization of the anatomic segment/identification of the infarct-related artery affect early care?

Case presentations

Localization of the anatomic segment/identification of the infarct-related artery and early management issues

Anterior myocardial infarction

Lateral and posterior acute myocardial infarction

Inferior and right ventricular acute myocardial infarction

Case conclusions

27 Can the ECG be used to predict cardiovascular risk and acute complications in ACS?

Case presentations

The electrocardiogram in the assessment of cardiovascular risk at presentation of acute coronary syndrome

Resolution of ST and T wave changes (see also Chapter 25)

Presence of Q waves or loss of R amplitude (see also Chapter 17)

ST segment depression (see also Chapter 15)

Reciprocal ST depression in STEMI

T wave inversion (see Chapter 15)

Lead aVR

Conduction abnormalities

Bundle branch block

Second- and third-degree heart block

Sustained ventricular arrhythmias

Atrial fibrillation

Heart rate

The normal or non-specific ECG

Multivariable risk algorithms

Case conclusions

Part 4 The Dysrhythmic ECG

28 Can the electrocardiogram determine the rhythm diagnosis in narrow complex tachycardia?

Case presentations

The electrocardiogram and the diagnosis of narrow complex tachycardia

Supraventricular tachycardia

Electrocardiographic characteristics of supraventricular tachycardias

Sinus tachycardia

Atrioventricular nodal re-entrant tachycardia

Atrioventricular re-entrant tachycardia

Atrial tachycardia

Multifocal atrial tachycardia

Junctional tachycardia

Atrial flutter

Atrial fibrillation

Case conclusions

29 Can the ECG guide treatment of narrow QRS tachycardia?

Case presentations

The ECG in narrow QRS tachycardia: management considerations

Narrow QRS tachycardias – regular

Narrow QRS tachycardias – irregular

Case conclusions

30 How can the ECG guide the diagnosis and management of wide complex tachycardias?

Case presentations

The ECG as a guide to the diagnosis and management of wide complex tachycardia

Wide complex tachycardia

Irregular WCT

Regular WCT

Electrocardiographic diagnosis

Management of the patient with wide complex tachycardia

Case conclusions

Acknowledgment

31 Can the ECG guide management in the patient with bradydysrhythmias?

Case presentations

The ECG and management of bradydysrhythmias

Pathophysiology and electrocardiographic presentation

Management

Case conclusions

32 What are the electrocardiographic indications for temporary cardiac pacing?

Case presentations

Electrocardiographic indications for temporary cardiac pacing

Indications for pacing in the patient with STEMI

Sinoatrial node dysfunction

Atrioventricular node blocks

Permanent pacemaker malfunction

Case conclusions

33 Can the ECG accurately diagnose pacemaker malfunction and/or complication?

Case presentations

The ECG and pacemaker malfunction/complication

Basics of pacemakers

Pacing modes

Evaluation for suspected pacemaker malfunction

Types of malfunction and associated electrocardiographic findings

Case conclusions

34 How can the ECG guide acute therapy in the Wolff Parkinson White (WPW) patient?

Case presentations

The ECG and acute therapy in the patient with WPW syndrome

Electrocardiographic findings suggestive of WPW syndrome

How to predict whether the patient is at low risk for sudden death?

Can the ECG guide acute therapy in the patient with WPW syndrome?

Case conclusions

Acknowledgment

35 What is the role of the ECG in PEA cardiac arrest scenarios?

Case presentations

The ECG in the PEA arrest scenario

Pathophysiology

PEA differential diagnosis

Specific causes of PEA

True PEA

Medication overdose

Pseudo-PEA

Conclusion

Case conclusions

Part 5 The ECG in Critical Care

36 What is the role of the ECG in the critically ill, non-coronary patient?

Case presentations

The role of the ECG in the critically ill, non-coronary patient

The role of the ECG and acute central nervous system events

The role of the ECG in pulmonary conditions

Role of the ECG in sarcoidosis

Role of ECG in gastrointestinal disorders: acute pancreatitis and biliary disease

Role of ECG in endocrinopathies

Case conclusions

37 Can the ECG distinguish between coronary and non-coronary etiologies in the critically ill patient?

Case presentations

The diagnostic use of electrocardiography in the evaluation of coronary versus non-coronary diagnoses in the critically ill

Summary

Case conclusions

Acknowledgments

38 What is the role of the ECG in therapeutic considerations/ medical management decisions in the critically ill patient?

Case presentations

How the ECG affects medical management in the critically ill patient

General management considerations in the dysrhythmic ICU patient

Polymorphic ventricular tachycardia and medications

The ECG and sedative drugs

ECG data acquisition and artifact

Pre-existing pacemakers and implanted cardioversion devices in the ICU

Hemodynamic monitoring and ECG

Identification of acute right heart syndromes in the ICU and implications on management

Case conclusions

39 Can the ECG predict risk in the critically ill, non-coronary patient?

Case presentations

The ECG and risk prediction in the critically ill, non-coronary patient

ICU complications

The role of the ECG in sepsis

Mechanical ventilation

Hemodialysis

The ECG in edematous states and anasarca

Case conclusions

40 What is the proper role of the ECG in the evaluation of patients with suspected PE?

Case presentations

The proper role of the ECG in the evaluation of patients with suspected PE

Appropriate evaluation of the patient with suspected PE

Variety of ECG findings in acute PE, their basis and usefulness

Atrial arrhythmia and PE

Prognostic utility of the ECG in acute PE

Case conclusions

41 What is the role and impact of the ECG in the patient with hyperkalemia?

Case presentations

The role and impact of the ECG in the critically ill patient with hyperkalemia

Hyperkalemia and the myocyte

Levels of hyperkalemia and ECG findings

Special ECG considerations in hyperkalemia

Case conclusions

Acknowledgments

42 What is the role and impact of the ECG in the patient with electrolyte abnormalities other than hyperkalemia?

Case presentations

The role and impact of the ECG in the patients with nonhyperkalemic electrolyte abnormalities

Hypokalemia

Calcium

Other electrolytes

Case conclusions

Acknowledgments

43 What is the role of the ECG in the hypothermic patient?

Case presentations

The role of the ECG in the hypothermic patient

Electrocardiographic morphology of hypothermia

Case conclusions

44 What are the non-ACS “deadly” ECG presentations?

Case presentations

Characteristic non-ACS deadly presentations

Cardiac tamponade and pericardial disease

Acute neurologic conditions

Thyrotoxicosis

Other endocrinopathies

Aortic aneurysm dissection

New-onset atrial tachydysrhythmias

Pneumothorax in the ICU

Case conclusions

Part 6 The Toxicologic ECG

45 How useful is the ECG in the evaluation of the poisoned patient?

Case presentations

Utilizing the ECG as a diagnostic tool in the poisoned patient

Sodium channel-blockade

Potassium efflux blockade

Na+/K+-ATPase blockade

Calcium channel- and beta-blockade

Case conclusions

46 Can the ECG guide management in the critically ill, poisoned patient?

Case presentations

Utilizing the ECG to guide management in the critically ill, poisoned patient

Case conclusions

47 Do characteristics of the QRS complex in the poisoned patient correlate with outcome?

Case presentations

The QRS complex in the poisoned patient

Case conclusions

48 What is the treatment for wide complex dysrhythmias in the poisoned patient?

Case presentations

Treatment for wide complex dysrhythmias in the poisoned patient

Sodium channel-blockade

Polymorphic ventricular tachycardia

Case conclusions

Part 7 Electrocardiogaphic Differential Diagnosis

49 What is the ECG differential diagnosis of ST segment elevation?

Case presentations

ST segment elevation

ECG differential diagnosis of ST segment elevation

Differential considerations in ST segment elevation

Case conclusions

50 What is the ECG differential diagnosis of ST segment depression?

Case presentations

ECG differential diagnosis of ST segment depression

The ST segment

Differential diagnosis of ST segment depression

Case conclusions

51 What is the ECG differential diagnosis of the abnormal T wave?

Case presentations

Differential diagnosis of the abnormal T wave

Cardiac conditions

Toxic/metabolic conditions

Toxic/metabolic conditionsNon-cardiac conditions

Case conclusions

52 What is the ECG differential diagnosis of narrow complex tachycardia?

Case presentations

Differential diagnosis of the narrow QRS complex tachycardia

QRS complex width

Regular narrow complex tachycardia

Atrial tachycardias

Atrioventricular tachycardias

Narrow complex ventricular tachycardia

Irregular Narrow Complex Tachycardias

Case conclusions

53 What is the ECG differential diagnosis of wide complex tachycardia?

Case presentations

Differential diagnosis of the wide QRS complex tachycardia

QRS complex width

Regular WCTs

WCTs with an irregular rate

Case conclusions

54 What is the ECG differential diagnosis of bradycardia?

Case presentations

The ECG differential diagnosis of bradydysrhythmias

Regular bradydysrhythmias

Irregular bradydysrhythmias

Case conclusions

55 What is the ECG differential diagnosis of the abnormally wide or large QRS complex?

Case presentations

Differential diagnosis of the abnormally large or wide QRS complex

Abnormally large QRS complex

Abnormally wide QRS complex

Case conclusions

56 What is the ECG differential diagnosis of a prolonged QT interval?

Case presentations

ECG differential diagnosis of the long QT interval

Differential diagnosis of a long QT interval

Case conclusions

Index

Dr Brady’s dedication – To my wife, King, for her constant support, patience, and guidance; and for my children, Lauren, Anne, Chip, and Katherine, for their love.

Dr Truwit’s dedication – To my wife Jeanne and my children, Jason, Matthew and Lauren without whom I could not be personally or professionally fulfilled nor accomplish as much.

This edition first published 2009, © 2009 by Blackwell Publishing Ltd

Blackwell Publishing was acquired by John Wiley & Sons in February 2007. Blackwell’s publishing program has been merged with Wiley’s global Scientific, Technical and Medical business to form Wiley-Blackwell.

Registered office: John Wiley & Sons Ltd, The Atrium, Southern Gate, Chichester, West Sussex, PO19 8SQ, UK

Editorial offices: 9600 Garsington Road, Oxford, OX4 2DQ, UKThe Atrium, Southern Gate, Chichester, West Sussex, PO19 8SQ, UK111 River Street, Hoboken, NJ 07030-5774, USA

For details of our global editorial offices, for customer services and for information about how to apply for permission to reuse the copyright material in this book please see our website at www.wiley.com/wiley-blackwell

The right of the author to be identified as the author of this work has been asserted in accordance with the Copyright, Designs and Patents Act 1988.

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, except as permitted by the UK Copyright, Designs and Patents Act 1988, without the prior permission of the publisher.

Wiley also publishes its books in a variety of electronic formats. Some content that appears in print may not be available in electronic books.

Designations used by companies to distinguish their products are often claimed as trademarks. All brand names and product names used in this book are trade names, service marks, trademarks or registered trademarks of their respective owners. The publisher is not associated with any product or vendor mentioned in this book. This publication is designed to provide accurate and authoritative information in regard to the subject matter covered. It is sold on the understanding that the publisher is not engaged in rendering professional services. If professional advice or other expert assistance is required, the services of a competent professional should be sought.

The contents of this work are intended to further general scientific research, understanding, and discussion only and are not intended and should not be relied upon as recommending or promoting a specific method, diagnosis, or treatment by physicians for any particular patient. The publisher and the author make no representations or warranties with respect to the accuracy or completeness of the contents of this work and specifically disclaim all warranties, including without limitation any implied warranties of fitness for a particular purpose. In view of ongoing research, equipment modifications, changes in governmental regulations, and the constant flow of information relating to the use of medicines, equipment, and devices, the reader is urged to review and evaluate the information provided in the package insert or instructions for each medicine, equipment, or device for, among other things, any changes in the instructions or indication of usage and for added warnings and precautions. Readers should consult with a specialist where appropriate. The fact that an organization or Website is referred to in this work as a citation and/or a potential source of further information does not mean that the author or the publisher endorses the information the organization or Website may provide or recommendations it may make. Further, readers should be aware that Internet Websites listed in this work may have changed or disappeared between when this work was written and when it is read. No warranty may be created or extended by any promotional statements for this work. Neither the publisher nor the author shall be liable for any damages arising herefrom.

Library of Congress Cataloging-in-Publication Data

Critical decisions in emergency and acute care electrocardiography / edited by William Brady, Jonathon Truwit.p. ; cm.Includes bibliographical references.ISBN 978-1-4051-5906-71. Electrocardiography. 2. Critical care medicine. I. Brady, William, 1960– II. Truwit, Jonathon Dean.[DNLM: 1. Electrocardiography. 2. Critical Care. 3. Decision Making. 4. Emergency Medical Services. WG 140 C934 2009]RC683.5.E5C75 2009616.1′207547—dc222008030326ISBN: 9781405159067

Foreword 1

In clinical medicine, there are a finite number of clinical skills that are considered essential areas of expertise in the management of critically ill patients. Such a short list might include advanced physical assessment, airway management, critical care problem solving, initiation of resuscitation efforts, identification of the need for early surgical intervention, and the immediate diagnostic interpretation of tests. One of the earliest and most common diagnostic studies performed in the critically ill patient is the electrocardiogram. The tremendous value of the electrocardiogram in the acutely and critically ill patient is unequivocally established – in fact, it is considered essential in management. Certainly, the basic electrocardiographic skill set is considered fundamental; the intricacies and nuances of advanced interpretation offers an abundance of clinical data that can alter patient course and outcome – and should also be considered fundamental in acute, emergency, and critical care settings. Drs. Brady and Truwit have assembled such a text which very nicely explores and reviews the impact of the electrocardiogram, from the prehospital arena and emergency department to the inpatient ward and critical care unit.

Patient safety and outcome goals have moved electrocardiographic analysis from the sole responsibility of the cardiologist to the point of care contact for our patients. Expertise in electrocardiographic interpretation is considered the standard of training in emergency medicine and critical care. Appropriately, there has been mounting pressure on acute care and critical care clinicians to rapidly and accurately assess electrocardiograms in a time dependent fashion. Critical time points have been established for electrocardiographic interpretation in acute ST segment elevation myocardial infarctions that directly impact patient treatment strategies, hospital resources and outcomes. Correct interpretation of the electrocardiogram alter treatment decisions for the management of non-ST elevation myocardial infarctions, dysrhythmias, undifferentiated cardiovascular diseases, and poisoning and ingestions. Additionally, electrocardiograms offer insights into other medical conditions that place acutely and critically ill patients in life threatening situations.

Developing expertise in electrocardiographic analysis requires dedicated study, practice and review. The management of critically ill patients at risk for cardiovascular compromise requires not just a basic familiarity in electro-gardiography, but an advanced interpretation skill level. Failure to develop expertise in the area of electrocardiography places patients at risk. Acute care electrocardiographic expertise is developed through meaningful self-education, clinical practice, and thoughtful review. Standardizing this process is essential because clinical experience alone is inadequate in addressing the breadth and extent of the required knowledge base.

This textbook on Critical Decisions in Electrocardiography represents an excellent example of standardizing the educational process of electrocardiography. By reviewing case scenarios, learners can explore and actively participate in critical decision making that is required for developing these essential diagnostic skills. The breadth of clinical presentations offers the learner an opportunity to review and reflect on high risk cardiovascular disease states that may not frequently present in their own clinical practice. The text allows for independent study and reflection that can lead to expertise in the field of electrocardiography, providing an integral component in the pursuit of a competency that our patients rely on and deserve.

Peter Delieux, MD

Professor of Clinical Medicine

Director of Emergency Medicine Services

Emergency Medicine Director of Resident and Faculty Development

Louisiana State University Health Sciences Center

New Orleans, LA, USA

Foreword 2

William Brady and Jon Truwit have done a masterful job at taking a topic that, while central to the Operating Room, ICU, Emergency Department environments, it is not usually the focus for the personnel regularly working in these areas. As a practicing pulmonary-intensivist, I know that when it comes to ECG abnormalities in the ICU we are exposed to anything and everything, often with very short notice and little time for diagnosis or to think about the most appropriate therapeutic interventions. The common problems such as atrial tachy arrhythmias, ischemic changes, ventricular tachycardia and signs of myocardial infarction occur with such frequency that it is relatively easy to maintain skills necessary to recognize and treat them. However, the uncommon problems are often seen so infrequently that recognition and treatment can be much more of a challenge. Thus Brady and Truwit in Critical Decisions in Emergency and Acute Care Electrocardiography have created a text that makes common and obscure ECG findings relevant and accessible.

Intensivists and others who do not regularly work in cardiac units must still maintain skills sufficient to recognize and provide at least the initial management of serious and/or life-threatening diseases manifesting in or resulting from abnormal ECGs. Though complex and challenging, these clinical problems are systematically dealt with by Brady and Truwit in a practical, easily readable format. The format of case presentations followed by a complete and systematic well-organized discussion is designed to give the reader information in a natural flow that facilitates assimilation into practice. The concise but very meaningful discussions of the controversies that loom large in some areas are well-articulated and serve to place much of the information into proper context. The fact that a whole chapter is devoted to the limitations of the ECG in clinical practice is a refreshing testament the pragmatism this volume brings to the field.

The ECG has been around a long time, has many limitations and must be interpreted in the light of the overall clinical presentation including prior probabilities. While the shape of the squiggles on the paper strips have not changed since Einthoven’s work in 1895, the true underlying diseases or processes (diagnoses) these represent have been greatly clarified. In addition the prognostic value of the ECG has greatly improved and we are still learning. Brady and Truwit efficiently takes us right up to the edge of the current state of knowledge.

Peter Delieux, MD

Professor of Clinical Medicine

Director of Emergency Medicine Services

Emergency Medicine Director of Resident and Faculty Development

Louisiana State University Health Sciences Center

New Orleans, LA, USA

Preface

Electrocardiography is performed widely throughout medicine, ranging from the clinician’s office in a scheduled, routine application to the critical care unit with an unanticipated decompensation during active resuscitation. And, of course, a multitude of other areas rely heavily on the ECG as valuable tool in the patient evaluation – the prehospital setting in an EMS unit, the emergency department, the surgical suite and post-anesthesia care area, among many others. In fact, it is appropriate to state that some form of electrocardiographic monitoring is one of the most widely applied diagnostic tests in clinical medicine today. Electrocardiography, whether single-lead monitoring for rhythm disorders or 12-lead analysis for ACS or other morphologic abnormality, remains one of the most cost-effective and useful tests in medicine – rapid, non-invasive, inexpensive, portable, easily interpreted – often providing clinical information that will make the difference between life and death.

In acute care medicine, whether it be the acute care ward, emergency department, or critical care unit, the ECG can assist in establishing a diagnosis, ruling-out various ailments, guiding the diagnostic and management strategies in the evaluation, providing indication for certain therapies, determining inpatient disposition location, offering risk assessment, and assessing end-organ impact of a syndrome. In more routine, though no less crucial, settings, the ECG assists in disease surveillance and screening in office-based evaluations as well as risk stratification in pre-operative assessments.

The ECG, similar to other clinical investigations, must be interpreted within the context of the clinical presentation. An understanding of this concept and its application at the bedside is crucial for the appropriate use of the ECG in clinical practice – and is the focus of this textbook, Critical Decisions in Emergency and Acute Care Electrocardiography. This textbook focuses on the breadth of acute care medicine – the ward, ED, OR, and critical care unit. Each section is organized around traditional topics such as acute coronary syndrome or dysrhythmia. Within each section, however, are a range of chapters, focusing on a specific use or clinical situation, involving the ECG; each chapter is presented in the form of an inquiry, followed by a series of cases, illustrating the issues, controversies, or questions. For instance, what are the electrocardiographic indications for urgent reperfusion therapy in ACS, can the ECG guide the clinician in the management of the patient with wide complex tachycardia, or what is the value of the 12-lead ECG in the poisoned patient? The chapter itself is the answer to the question with appropriate electrocardiographic examples and adequate supporting evidence.

This work stresses the value of the ECG in the range of clinical situations encountered daily by healthcare providers – it illustrates the appropriate applications of the electrocardiogram in acute care medicine today. We have enjoyed its creation – we hope that you the clinician will find it of value in your care of the patient.

William J Brady & Jonathon D TruwitCharlottesville, VA, USASeptember 2008

Section Editors

Ellen C. Keeley, MD

Associate Professor of Internal Medicine, Department of Internal Medicine, Division of Cardiology, University of Virginia, Charlottesville, VA, USA

Andrew Perron, MD

Program Director, Department of Emergency Medicine, Maine Medical Center, Portland, ME, USA

Stephen W. Smith, MD

Faculty Emergency Physician, Hennepin County Medical Center, Associate Professor of Emergency Medicine, University of Minnesota School of Medicine, Minneapolis, MN, USA

Amal Mattu, MD, FAAEM, FACEP

Director, Emergency Medicine Residency Associate Professor, Department of Emergency Medicine, University of Maryland School of Medicine, Baltimore, MD, USA

Ajeet Vinayak, MD

Assistant Professor of Medicine, Pulmonary and Clinical Care Division, Department of Medicine, University of Virginia, Charlottesville, VA, USA

Christopher P. Holstege, MD

Associate Professor, Department of Emergency Medicine; Director, Division of Medical Toxicology, University of Virginia School of Medicine, Charlottesville, VA, USA

Theodore C. Chan, MD

Professor and Medical Director, Department of Emergency Medicine, University of California, San Diego, CA, USA

Richard A. Harrigan, MD

Professor, Department of Emergency Medicine, Temple University, Philadephia, PA, USA

Contributors

Michael Abraham, MD

Attending Physician, Department of Emergency Medicine, Upper Chesapeake Medical Center, Bel Air, MD, USA

Khaled Bachour, MD

Fellow, Division of Cardiology, Department of Internal Medicine, Harper Hospital, Wayne State University School of Medicine, Detroit, MI, USA

Billie Barker, MD, USA

Pulmonary & Critical Care Fellow, Department of Internal Medicine, Division of Pulmonary & Critical Care, University of Virginia, Charlottesville, VA, USA

Stefan C. Bertog, MD

Interventional Cardiology Veterans Administration Medical Center, University of Minnesota, Minneapolis, MN, USA

Michael A. Bohrn, MD, FAAEM, FACEP

Associate Residency Program Director, Clinical Assistant Professor, Department of Emergency Medicine, York Hospital, York, PA, USA

Michael C. Bond, MD, FAAEM

Assistant Residency Program Director, Assistant Professor, Department of Emergency Medicine, University of Maryland School of Medicine, Baltimore, MD, USA

Christopher T. Bowe, MD, FACEP

Associate Residency Program Director, Assistant Professor, Emergency Medicine, Department of Emergency Medicine, Maine Medical Center, Portland, ME, USA

David Burt, MD