Cardiovascular System at a Glance (eBook)

Philip Aaronson is Reader in Pharmacology andTherapeutics at King's College, London Jeremy Ward is Head of Department of Physiology andProfessor of Respiratory Cell Physiology at King's College,London Michelle Connolly is Academic Foundation Doctor atthe Royal Free Hospital, London

Title page 5
Copyright page 6
Contents 7
Preface 8
Recommended reading 8
Acknowledgements 9
List of abbreviations 10
Introduction 12
1: Overview of the cardiovascular system 12
Blood vessel functions 13
Anatomy and histology 14
2: Gross anatomy and histology of the heart 14
Gross anatomy of the heart (Figure 2a) 15
Structure of the myocardium 15
Coronary circulation (Figure 2f) 15
3: Vascular anatomy 16
The systemic circulation 17
Arteries 17
Arterial anastomoses 17
Veins 17
The pulmonary circulation 17
The splanchnic circulation 17
The lymphatic system 17
4: Vascular histology and smooth muscle cell ultrastructure 18
Exchange vessel structure 19
Smooth muscle cell ultrastructure 19
Blood and body fluids 20
5: Constituents of blood 20
Plasma 21
Ionic composition 21
Proteins 21
Blood cells 21
Erythrocytes 21
Leucocytes (white cells) and platelets 21
6: Erythropoiesis, haemoglobin and anaemia 22
Erythropoiesis 22
Haemoglobin 23
Anaemia 23
7: Haemostasis 24
Primary haemostasis (Figure 7a) 25
Formation of the blood clot (Figures 7b,c) 25
Inhibitors of haemostasis and fibrinolysis 25
Defects in haemostasis 25
8: Thrombosis and anticoagulants 26
Thrombosis 27
Antiplatelet drugs (Figure 8b) 27
Anticoagulant drugs (Figure 8c) 27
Some laboratory investigations 27
9: Blood groups and transfusions 28
Blood groups 28
The ABO system 28
Rh groups 29
Other blood groups 29
Complications of blood transfusions 29
Blood storage 29
Cellular physiology 30
10: Membrane potential, ion channels and pumps 30
Resting membrane potential (Figure 10a) 31
Ion channels and gating (Figure 10b) 31
Ion pumps and exchangers (Figure 10c) 31
Ion pumps and membrane potential 31
11: Electrophysiology of cardiac muscle and origin of the heart beat 32
Ventricular muscle action potential (Figure 11a) 33
Initiation of the action potential 33
The plateau (phase 2) 33
Repolarization (phase 3) 33
Role of Na+–Ca2+ exchange 33
Sinoatrial node 33
Other regions of the heart (Figure 11d) 33
12: Cardiac muscle excitation–contraction coupling 34
Initiation of contraction 35
Generation of tension 35
Relaxation mechanisms 35
Regulation of contractility 35
Influence of heart rate 35
13: Electrical conduction system in the heart 36
Electrical conduction in cardiac muscle (Figure 13a) 37
Conduction pathways in the heart (Figure 13b) 37
Sinoatrial node 37
Atrial conduction 37
The atrioventricular node 37
Bundle of His and Purkinje system 37
Abnormalities of impulse generation or conduction (see also Chapters 48–50) 37
14: The electrocardiogram 38
Recording the ECG 39
General features of the ECG (Figure 14b) 39
Basic interpretation of the ECG (Figure 14e) 39
15: Vascular smooth muscle excitation–contraction coupling 40
Regulation of contraction by Ca2+ and myosin phosphorylation (see shaded area in left cell of Figure 15) 40
Vasoconstricting mechanisms 41
Effects of IP3 and diacylglycerol 41
Ca2+ influx mechanisms 41
Ca2+ removal and vasodilator mechanisms (see right cell of Figure 15) 41
The pressure–volume loop 43
Heart sounds and murmurs 43
Form and function 42
16: Cardiac cycle 42
17: Control of cardiac output 44
Ventricular function curves 45
Role of Starling’s law 45
The autonomic nervous system 45
Vascular function curves and Guyton’s analysis 45
18: Haemodynamics 46
Relationships between pressure, resistance and flow 46
Blood viscosity 47
Laminar flow 47
Wall tension 47
19: Blood pressure and flow in the arteries and arterioles 48
Factors controlling arterial blood pressure 48
Blood pressure and flow in the arteries 48
Arterioles and vascular resistance 49
20: The microcirculation and lymphatic system, and diapedesis 50
Organization of the microcirculation 50
Movement of solutes across the capillary wall 51
The blood–brain barrier 51
Diapedesis 51
The lymphatic system 51
21: Fluid filtration in the microcirculation 52
Movement of water across the capillary wall 52
Water filtration and absorption 53
Pulmonary and systemic oedema 53
22: The venous system 54
Venous arterial compliance 55
The veins as capacitance vessels 55
Effects of posture 55
The skeletal muscle pump 55
The respiratory pump 55
Effect of cardiac contraction 55
23: Local control of blood flow 56
Autoregulation 56
Metabolic and reactive hyperaemia 57
Metabolic factors 57
Other local mechanisms 57
24: Regulation of the vasculature by the endothelium 58
Nitric oxide 58
Other endothelium-derived relaxing mechanisms 59
Endothelium-derived constricting factors 59
Endothelium in cardiovascular disease 59
25: The coronary, cutaneous and cerebral circulations 60
Coronary circulation 60
Cutaneous circulation 61
Cerebral circulation 61
26: The pulmonary, skeletal muscle and fetal circulations 62
The pulmonary circulation 62
The skeletal muscle circulation 63
The fetal circulation 63
Circulatory changes at birth 63
Integration and regulation 64
27: Cardiovascular reflexes 64
Intrinsic cardiovascular reflexes 64
The baroreceptor reflex 64
Cardiopulmonary reflexes 65
Chemoreceptor reflexes 65
The CNS ischaemic response 65
Extrinsic reflexes 65
Central regulation of cardiovascular reflexes 65
28: Autonomic control of the cardiovascular system 66
The sympathetic system 67
Effects on the heart 67
Effects on the vasculature 67
The parasympathetic system 67
Effects on the heart 67
Effects on the vasculature 67
29: The control of blood volume 68
Role of sodium and osmoregulation 69
Control of Na+ and blood volume by the kidneys 69
Antidiuretic hormone in volume regulation 69
30: Cardiovascular effects of exercise 70
Effects of exercise on plasma volume 71
Regulation and coordination of the cardiovascular adaptation to exercise 71
Systemic effects mediated by autonomic reflexes 71
Effects of local metabolites on muscle and heart 71
Effects of training 71
31: Shock and haemorrhage 72
Haemorrhagic shock 72
Immediate compensation 73
Medium- and long-term mechanisms 73
Complications and irreversible (refractory) shock 73
Other types of hypovolaemic shock 73
Low-resistance shock 73
History, examination and investigations 74
32: History and examination of the cardiovascular system 74
History 74
Examination 75
33: Cardiovascular investigations 76
X-rays (chest radiography) 77
Echocardiography and Doppler ultrasound 77
Catheterization and angiography 77
Imaging 77
Pathology and therapeutics 78
34: Risk factors for cardiovascular disease 78
Modifiable risk factors 78
Fixed risk factors 79
Family history of CVD 79
Male sex 79
35: ?-Blockers, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers and Ca2+ channel blockers 80
?-Adrenoceptor antagonists (?-blockers) 80
Angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers 81
Ca2+ channel blockers 81
36: Hyperlipidaemias 82
Lipoproteins and lipid transport 82
Hyperlipidaemias: types and treatments 83
37: Atherosclerosis 84
Pathogenesis of atherosclerosis 85
Oxidized low-density lipoprotein, macrophages and atherogenesis 85
Clinical consequences of advanced atherosclerosis 85
38: Treatment of hypertension 86
39: Mechanisms of primary hypertension 88
The kidney and sodium in hypertension 88
Neurogenic and humoral theories of hypertension 89
Vascular remodelling 89
Secondary hypertension 89
Consequences of hypertension 89
40: Stable and variant angina 90
Pathophysiology 90
Diagnosis 91
Prognosis 91
Stable angina 91
Variant angina 91
Management 91
41: Pharmacological management of stable and variant angina 92
Anti-anginals 92
?-Adrenergic receptor blockers 92
Ca2+-channel blockers (also Ca2+ antagonists) 93
Nitrovasodilators 93
Other anti-anginals 93
Management of variant angina 93
Drugs for secondary prevention of cardiovascular disease 93
42: Acute coronary syndromes: Unstable angina and non-ST segment elevation myocardial infarction 94
Pathophysiology of UA/NSTEMI 95
Risk stratification 95
Management 95
Drug treatment of UA/NSTEMI (see also Chapter 8 for drug mechanisms) 95
43: Revascularization 96
Revascularization vs medical management: which patients benefit? 97
PCI vs CABG 97
Benefits of revascularization 97
44: Pathophysiology of acute myocardial infarction 98
Role of thrombosis in MI 98
Mechanisms and consequences of plaque rupture 98
Evolution of the infarct 99
45: Acute coronary syndromes: ST segment elevation myocardial infarction 100
Symptoms and signs 100
Investigations 100
Management 100
Thrombolytic agents 101
Other drugs used in acute myocardial infarction 101
Complications of acute myocardial infarction 101
46: Heart failure 102
Causes of heart failure 103
Pathophysiology 103
Consequences of compensation (Figure 46b) 103
Myocardial dysfunction and remodelling 103
47: Treatment of chronic heart failure 104
ACEI and other vasodilators 104
?-Receptor blockers 105
Aldosterone antagonists 105
Diuretics 105
Cardiac glycosides 105
48: Mechanisms of arrhythmia 106
Disorders of impulse generation: latent pacemakers and triggered automaticity 106
Abnormal impulse conduction: re-entry 107
The sympathetic nervous system and arrhythmias 107
49: Supraventricular tachyarrhythmias 108
50: Ventricular tachyarrhythmias and non-pharmacological treatment of arrhythmias 110
Specific ventricular tachyarrhythmias 110
Non-pharmacological treatment for arrhythmias 111
51: Pharmacological treatment of arrhythmias 112
Class I drugs 113
Class II drugs 113
Class III drugs 113
Class IV drugs, adenosine and digoxin 113
52: Pulmonary hypertension 114
Types of pulmonary hypertension 114
Pulmonary arterial hypertension 115
Pathophysiology 115
Clinical findings and diagnosis 115
Management 115
53: Diseases of the aortic valve 116
Aortic stenosis 116
Causes 116
Pathophysiology 116
Clinical features 117
Investigations 117
Management 117
Aortic regurgitation 117
Causes 117
Pathophysiology 117
Clinical features 117
Investigations 117
Management 117
54: Diseases of the mitral valve 118
Mitral stenosis 118
Causes 118
Pathophysiology 118
Clinical features 119
Management 119
Mitral regurgitation 119
Causes 119
Pathophysiology 119
Clinical features 119
Management 119
55: Genetic and congenital heart disease 120
Hypertrophic obstructive cardiomyopathy 120
Channelopathies 120
Congenital heart disease 121
Ventricular septal defect 121
Patent (or persistent) ductus arteriosus 121
Transposition of the great arteries 121
Fallot’s tetralogy 121
Atrial septal defects 121
Self-assessment 122
Case studies and questions 122
Case studies answers 125
Index 128