Acute Cardiac Care

Angela M. Kucia is a Clinical Practice Consultant in Acute Cardiac Assessment at the Queen Elizabeth and Lyell McEwin Hospitals in Adelaide, South Australia. Angela also lectures in postgraduate cardiovascular nursing at the University of South Australia and has been involved in acute cardiac nursing for twenty years. Tom Quinn is Professor of Clinical Practice at the University of Surrey and also Visiting Professor of Cardiac Nursing at Coventry University, UK. Tom has extensive clinical experience both in and out of hospital, and was closely involved in developing and implementing the National Service Framework for Coronary Heart Disease and related policies in England.

Contributors vii

Foreword ix

Preface xi

1 Mechanics of the Cardiovascular System 1
B. Greaney & A.M. Kucia

Overview 1

Basic heart anatomy 1

The cardiac cycle 2

Cardiac output 6

Conclusion 7

2 Regulation of Cardiac and Vascular Function 8
B. Greaney & A.M. Kucia

Overview 8

Central nervous system regulation of the cardiovascular system 8

Vasomotor control 9

Baroreceptors 10

Chemoreceptors 10

Humoral control 11

Electrolytes 13

Conclusion 13

3 Cardiac Electrophysiology 15
B. Greaney & A.M. Kucia

Overview 15

Cardiac cells 15

The action potential 16

The action potential in non-pacemaker cells 17

The cardiac conduction system 18

The electrocardiogram 20

Conclusion 20

4 The Coronary Circulation 21
B. Greaney & A.M. Kucia

Overview 21

The coronary circulation 21

The left main coronary artery 22

The LAD artery 23

The LCX or CX artery 23

The right coronary artery 23

Collateral circulation 23

Microvascular circulation 24

Coronary venous circulation 24

5 Risk Factors for Cardiovascular Disease 26
A.M. Kucia & E. Birchmore

Overview 26

Classification of risk factors for CVD 26

Biomedical risk factors 27

Behavioural risk factors 32

Psychosocial risk factors 34

Conclusion 35

6 Populations at Risk 39
T. Wachtel, R. Webster & J. Smith

Overview 39

Risk factors for CVD 39

Clarifying risk 40

Risk assessment tools 40

Populations at increased risk 41

Targeting treatment 45

Using what we know 46

Conclusion 46

7 Evidence-Based Practice 50
D. Evans & T. Quinn

Overview 50

The need for change 50

Evidence-based practice 51

Barriers to the evidence 56

Conclusion 57

8 Ethics of Research in Acute Cardiac Care 59
B.F. Williams & A.M. Kucia

Overview 59

Evidence-based medicine and clinical trials 60

Informed consent for trial participation 60

What is an ethical dilemma? 62

Genetic research 63

Considering an offer for the unit to participate in a clinical trial 63

Ethical issues in marketing and pricing of new pharmaceutical agents 64

Conclusion 64

9 Cardiovascular Assessment 67
A.M. Kucia & S.A. Unger

Overview 67

Health history 67

Physical examination 70

Conclusion 79

10 Electrocardiogram Interpretation 81
A.M. Kucia & C. Oldroyd

Overview 81

Normal sequence of depolarisation and repolarisation 81

Theoretical basis of electrocardiography 83

Determining the cardiac axis 85

Determination of heart rate and electrocardiographic intervals 86

Chamber enlargement 88

Bundle branch block 88

ECG changes related to myocardial ischaemia and infarction 91

Obtaining a 12-lead ECG 94

Conclusion 97

11 Cardiac Monitoring 99
A.M. Kucia & C. Oldroyd

Overview 99

ECG monitoring systems and lead formats 100

Indications for arrhythmia monitoring 103

Nursing considerations in the care of the patient with ECG monitoring 103

12 Laboratory Tests 109
D. Barrett, L. Jesuthasan & A.M. Kucia

Overview 109

Generic laboratory tests 109

Electrolytes 110

Renal function 110

Glucose measurement 111

Lipid profiles 111

Complete blood examination 111

Clotting screen 112

Biochemical markers 112

Markers of myocardial necrosis 112

Cardiac natriuretic peptides 113

C-reactive protein 114

Conclusion 114

13 Diagnostic Procedures 116
L. Belz, K. Mishra, S.A. Unger & A.M. Kucia

Overview 116

Chest X-ray 116

Cardiac catheterisation (angiogram) 118

Echocardiography 124

Stress testing 125

Magnetic resonance imaging 130

Computerised tomography 132

Electrophysiology studies 132

Conclusion 133

14 Sudden Cardiac Death 137
T. Quinn & P. Gregory

Overview 137

Definitions 138

Burden of disease and risk factors for SCD 138

Sudden death in the young (including athletes) 139

Structural abnormalities 140

Cardiomyopathies and SCD 141

Genetic syndromes and SCD 141

Conclusion 143

15 Out-of-Hospital Cardiac Arrest and Automated External Defibrillation 145
P. Gregory & T. Quinn

Overview 145

Out-of-hospital cardiac arrest 146

Hazards to the victim and rescuer 146

Recognition of cardiac arrest and BLS 147

Automated external defibrillation 149

Conclusion 150

16 Ethical Issues in Resuscitation 152
A.M. Kucia & B.F. Williams

Overview 152

Guiding ethical principles in resuscitation 152

Futility 153

Rights of the individual versus the

needs of society 153

Patient perceptions of resuscitation 154

Introducing the DNR conversation 154

Witnessed resuscitation 154

Withdrawal of treatment 156

Organ donation 157

Training and research with the newly dead 157

17 Pathogenesis of Acute Coronary Syndromes 161
A.M. Kucia & J.D. Horowitz

Overview 161

Acute coronary syndrome 162

Atherosclerosis 162

Endothelial dysfunction 162

Plaque disruption 162

Inflammation 163

Thrombosis 164

Vasoconstriction 164

Conclusion 164

18 Presentations of Acute Coronary Syndromes 167
A.M. Kucia & J.F. Beltrame

Overview 167

Angina pectoris 167

Stable angina 168

The acute coronary syndromes 168

Global trends in ACS presentations 170

Clinical history in ACS 170

Physical examination in ACS patients 172

The 12-lead electrocardiogram in ACS 173

Cardiac markers in ACS 174

Clinical assessment and risk stratification in ACS 174

Conclusion 175

19 Risk Stratification in Acute Coronary Syndromes 178
A. Day, C. Ryan & T. Quinn

Overview 178

Introduction 178

Risk stratification 179

Risk stratification guidelines 180

Risk scores 181

Chest pain units 182

Conclusion 183

20 Reducing Time to Treatment 185
T. Quinn & A. Day

Overview 185

Benefits of early reperfusion 185

Identifying and addressing delays 186

Conclusion 190

21 Reperfusion Strategies 193
C.J. Zeitz & T. Quinn

Overview 193

Pathogenesis of STEMI 193

Principles of reperfusion strategies 194

Options for reperfusion 194

Strategies for reducing treatment time delays 199

Detecting and managing failed reperfusion 199

Preventing and detecting re-occlusion 200

Conclusion 201

22 Adjunct Pharmacological Agents in Acute Coronary Syndromes 204
A.M. Kucia & J.D. Horowitz

Overview 204

Anti-ischaemic therapies 205

Antiplatelet and anticoagulant therapy 209

Inhibitors of the renin-angiotensinaldosterone system 215

Statins 216

Conclusion 216

23 Arrhythmias 222
C. Oldroyd & A.M. Kucia

Overview 222

Basic electrophysiology 223

Mechanisms of arrhythmia generations 223

Cardiac monitoring 225

Rhythm interpretation 225

Determining the rhythm 227

Tachyarrhythmias 232

Asystole 238

Treatment of arrhythmias 239

Conclusion 241

24 In-Hospital Resuscitation 243
C. Oldroyd, T. Quinn & P. Whiston

Overview 243

Introduction 244

Prevention: systems for identifying patients at risk of cardiac arrest 245

Early recognition and management of critically ill patients 246

In-hospital resuscitation 248

Working within your scope of practice 250

Audit and data collection 253

Conclusion 253

25 Acute Heart Failure 257
T. Quinn

Overview 257

Introduction 257

Establishing the diagnosis 258

Management specifics 261

Refractory AHF 264

Dignity, communication and preventing complications: ‘back to basics’ 265

Managing chronic heart failure better to reduce the need for re-hospitalisation 266

Conclusion 266

26 Convalescence 269
P. Davidson & R. Webster

Overview 269

Introduction 270

Assessment and identification of patient needs 272

High risk groups 272

Promoting self-management in the convalescent phase 272

Particular concerns of spouses and family members 273

Accommodating convalescence and discharge planning following an acute cardiac event 274

Models of intervention to facilitate convalescence and secondary prevention 274

Nursing strategies to promote convalescence 275

Palliative care 276

Conclusion 276

27 Discharge Planning and Secondary Prevention 280
R. Webster & P. Davidson

Overview 280

Discharge planning 280

Secondary prevention 281

Provision of secondary prevention 282

Components of secondary prevention 283

Cardio-protective drug therapy 289

Challenges in secondary prevention 290

Conclusion 291

Index 297