Critical Decisions in Emergency and Acute Care Electrocardiography

William Brady, Department of Emergency Medicine, University of Virginia School of Medicine Jonathon Truwit, Pulmonary and Critical Care Medicine, University of Virginia Health Systems

Section Editors vii

Contributors viii

Preface xi

Forewords xii

Part 1 The ECG in Clinical Practice 1

1 What are the clinical applications of the ECG in emergency and critical care? 3

2 What are the indications for the ECG in the pediatric emergency department? 12

3 What are the limitations of the ECG in clinical practice? 19

4 Is the ECG indicated in stable non-cardiac patients admitted to the hospital? 24

5 What is the use of the ECG in preoperative assessment and cardiovascular risk stratification? 28

6 Which patients benefit from continuous electrocardiographic monitoring during hospitalization? 33

Part 2 The ECG in Cardinal Presentations 39

7 How should the ECG be used in the syncope patient? 41

8 How should the ECG be used in the chest pain patient? 49

9 How should the ECG be used in the dyspneic patient? 58

10 How should the ECG be used in the patient with altered mentation? 64

11 How should the ECG be used in the patient during and following cardiac arrest? 69

12 What is the impact/proper role of the ECG in the undifferentiated cardiorespiratory failure patient? 75

Part 3 The ECG in ACS 83

13 What is the role of the ECG in ACS? 85

14 What pseudoinfarction patterns mimic ST elevation myocardial infarction? 92

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? 103

16 What is a hyperacute T Wave? 115

17 What is the significance of Q waves? 122

18 What are the ECG indications for additional electrocardiographic leads (including electrocardiographic body-surface mapping) in chest pain patients? 128

19 What further diagnostic adjuncts to the standard 12-lead ECG may help to diagnose ACS? 138

20 Is serial electrocardiography (serial ECGs and ST segment monitoring) of value in the ECG diagnosis of ACS? 148

21 What QRS complex abnormalities result in ST segment elevation that may mimic or obscure AMI? 155

22 What are the electrocardiographically silent areas of the heart? 167

23 What is the value of the prehospital acquired 12-lead Ecg? 176

24 What are the electrocardiographic indications for reperfusion therapy? 182

25 What are the ECG manifestations of reperfusion and reocclusion? 195

26 Does localization of the anatomic segment/identification of the infarct-related artery affect early care? 204

27 Can the ECG be used to predict cardiovascular risk and acute complications in ACS? 216

Part 4 The Dysrhythmic ECG 231

28 Can the electrocardiogram determine the rhythm diagnosis in narrow complex tachycardia? 233

29 Can the ECG guide treatment of narrow QRS tachycardia? 244

30 How can the ECG guide the diagnosis and management of wide complex tachycardias? 251

31 Can the ECG guide management in the patient with bradydysrhythmias? 267

32 What are the electrocardiographic indications for temporary cardiac pacing? 276

33 Can the ECG accurately diagnose pacemaker malfunction and/or complication? 284

34 How can the ECG guide acute therapy in the Wolff Parkinson White (WPW) patient? 295

35 What is the role of the ECG in PEA cardiac arrest scenarios? 303

Part 5 The ECG in Critical Care 315

36 What is the role of the ECG in the critically ill non-coronary patient? 317

37 Can the ECG distinguish between coronary and non-coronary etiologies in the critically ill patient? 326

38 What is the role of the ECG in therapeutic considerations/ medical management decisions in the critically ill patient? 335

39 Can the ECG predict risk in the critically ill noncoronary patient? 345

40 What is the proper role of the ECG in the evaluation of patients with suspected PE? 354

41 What is the role and impact of the ECG in the patient with hyperkalemia? 362

42 What is the role and impact of the ECG in the patient with electrolyte abnormalities other than hyperkalemia? 371

43 What is the role of the ECG in the hypothermic patient? 378

44 What are the non-ACS “deadly” ECG presentations? 384

Part 6 The Toxicologic ECG 395

45 How useful is the ECG in the evaluation of the poisoned patient? 397

46 Can the ECG guide management in the critically ill poisoned patient? 402

47 Do characteristics of the QRS complex in the poisoned patient correlate with outcome? 407

48 What is the treatment for wide complex dysrhythmias in the poisoned patient? 412

Part 7 Electrocardiogaphic Differential Diagnosis 417 

49 What is the ECG differential diagnosis of ST segment elevation? 419

50 What is the ECG differential diagnosis of ST segment depression? 428

51 What is the ECG differential diagnosis of the abnormal T wave? 436

52 What is the ECG differential diagnosis of narrow complex tachycardia? 444

53 What is the ECG differential diagnosis of wide complex tachycardia? 452

54 What is the ECG differential diagnosis of bradycardia? 461

55 What is the ECG differential diagnosis of the abnormally wide or large QRS complex? 469

56 What is the ECG differential diagnosis of a prolonged QT interval? 479