Atrial Fibrillation

1 The Cardiac Conducting System and Its Autonomic Control.- Anatomy of the Conducting System.- Basic Cardiac Electrophysiology.- The Initiation and Propagation of the Cardiac Impulse.- Resetting the Sinoatrial Node Pacemaker.- The Spread of the Impulse Through the Atria.- The Functioning of the Atrioventricular Node.- Does the Atrioventricular Node Conduct?.- Autonomic Innervation of the Heart.- Autonomic Control of the Sinoatrial Node.- Autonomic Control of the Atrioventricular Node.- 2 The Pathophysiology of Atrial Fibrillation.- Pathology.- The Electrophysiology of Atrial Fibrillation.- Electrophysiological Factors that Predispose to Atrial Fibrillation.- Initiation of Atrial Fibrillation.- The Mapping of Atrial Flutter and Fibrillation: The Essential Distinction Between Them.- The Ventricular Response in Atrial Fibrillation.- The Input to the Atrioventricular Node.- The Ventricular Response in Atrial Fibrillation.- The Role of the Autonomic Nervous System in Atrial Fibrillation.- Autocorrelation and the Baroflex.- Fibrillatory Waves in Atrial Fibrillation.- The Brody Phenomenon in Atrial Fibrillation.- The QT Interval in Atrial Fibrillation.- Is the QT Interval in Atrial Fibrillation Different from that in Sinus Rhythm?.- Atrial Fibrillation and the Wolff-Parkinson-White Syndrome.- Aberration in Atrial Fibrillation.- 3 Models of the Atrioventricular Node.- The Electrophysiological Model of the Atrioventricular Node.- Analogue Models of the Atrioventricular Node.- Mathematical Models of the Atrioventricular Node in Atrial Fibrillation.- The Model of Cohen et al. (1983).- The Atrioventricular Node as a Biological Oscillator.- The Model of Guevara and Glass (1982).- Resetting the Oscillator.- The Response of a Sine-Wave Oscillator to a Rapid Random Input.- The Effect of a Refractory Period on the Behaviour of the Sine-Wave Model of the Atrioventricular Node.- What Values Should Be Assigned to the Sine-Wave Model’s Parameters?.- More Electrophysiological Phenomena: Ventricular Extrasystoles.- The “Compensatory Pause” in Atrial Fibrillation.- Peeling Back Refractoriness.- The Effect of Right Ventricular Pacing in Atrial Fibrillation.- The Wolff-Parkinson-White Syndrome.- Conclusions.- Phase Resetting: An Achilles Heel.- 4 The Measurement of Cardiac Output in Sinus Rhythm and Atrial Fibrillation.- Assessment of Cardiac Function.- The Assessment of Cardiovascular Function.- Measuring Volumetric Cardiac Output by the Fick Method..- The Indirect Fick Technique.- Thermodilution.- Reproducibility of Thermodilution.- Measurement of Cardiac Output by Echocardiography and Doppler Ultrasound.- Measurement of Aortic Cross-Sectional Area.- Measurement of Stroke Distance.- Linear Cardiac Output.- Relationship Between Body Surface Area and Aortic Cross-Sectional Area.- Effect of Age and Blood Pressure on Aortic Size and Stroke Distance.- Expectations of Linear Cardiac Output.- Comparison between Thermodilution and Doppler Ultrasound.- Relationship Between Linear and Volumetric Cardiac Output.- Application of Linear Cardiac Output Measurement to Atrial Fibrillation.- Average Stroke and Minute Distance in Atrial Fibrillation.- Beat-to-Beat Measurement of Stroke Output.- 5 The Haemodynamics of Atrial Fibrillation: The Development of a Model of Left Ventricular Function.- The Relationship Between Time and Volume of the Pulse.- Is Pulse Volume Irregularly Irregular?.- Derivation of a Mathematical Model of Left Ventricular Function.- The Physiological Basis for the Mathematical Model of Left Ventricular Function.- Effect of RR—1 on Stroke Distance: Preload.- Effect of RR—1 on Stroke Distance: Contractility.- The Effect of RR-1 on Stroke Distance: Afterload.- Effect of RR-2 on Stroke Distance.- Balance of Effects of RR-1 and RR-2.- Pulsus Alternans.- Application of the Mathematical Model of Left Ventricular Function.- Graphical Presentation of Multiple Regression Equation.- Haemodynamic Consequences of Atrial Fibrillation.- Venous Return.- Ventricular Filling.- Mitral Regurgitation.- Coronary Blood Flow.- Regional Blood Flow.- Systolic Time Intervals.- Endocrine Consequences of Atrial Fibrillation.- 6 The Haemodynamics of Atrial Fibrillation: The Effect of Ventricular Rate on Cardiac Output.- Further Information from Multiple Regression Analysis.- Three Haemodynamic Profiles.- Relationship between Stroke and Minute Output.- The Contribution of the Force-Frequency Effect to Maintenance of Cardiac Output at High Ventricular Rates.- The Predicted Effect of Heart Rate on Cardiac Output in Mitral Stenosis.- Effect of Irregularity Per Se on Cardiac Output.- The Ventricular Rate for Maximum Cardiac Output.- The Predicted Ventricular Rate for Maximal Cardiac Output 122 Relationship Between Slope of the Md/Mean VR Graph and Ventricular Rate.- Group Relationship Between Mean R-R Interval and Stroke Distance.- The Magnitude of the Effect of Ventricular Rate on Cardiac Output.- The Ventricular Rate for Maximum Cardiac Output: Sinus Rhythm.- Comparison of Atrial Fibrillation and Sinus Rhythm.- What is Meant by “Control” of Ventricular Rate?.- A New Concept of Control of the Ventricular Rate in Atrial Fibrillation.- 7 The Use of the Haemodynamic Model of Atrial Fibrillation for Evaluating Drug Action.- More Haemodynamic Profiles.- Additional Haemodynamic Data Derived from Stroke Distance.- A Pilot Study of the Effect of Enoximone in Atrial Fibrillation.- The Effect of Enoximone on the Haemodynamic Model.- Control of Ventricular Rate While on Enoximone.- A Placebo Controlled Trial of Enoximone and Digoxin in Atrial Fibrillation.- Conclusions.- 8 The Autonomic Control of Ventricular Rate in Atrial Fibrillation.- Respiratory Sinus Arrhythmia.- Quantifying Respiratory Sinus Arrhythmia.- Cheyne-Stokes Respiration.- Respiratory Variation of P-R Intervals.- Modelling the Effect of the Vagus on the Atrioventricular Node.- Respiratory Variation of Ventricular Rate in Atrial Fibrillation.- Modelling the Action of the Vagus on the Ventricular Response to Atrial Fibrillation.- Measurement of Baroreflex Function.- Ramp Method.- Neck-Suction Method.- Integration of Respiratory Sinus Arrhythmia and the Baroreflex.- The Frequency Response of the Heart Rate Control System.- A Systems Approach to Heart Rate Control.- The Effect of Ventricular Rate on Blood Pressure in Atrial Fibrillation.- The Effect of Ventricular Rate on Blood Pressure in Sinus Rhythm.- Regulation of Ventricular Rate in Atrial Fibrillation.- Conclusions.- 9 Clinical Aspects of Atrial Fibrillation.- Epidemiology.- Incidence.- Prevalence.- Prognosis.- Aetiology.- Coronary Artery Disease.- Myocardial Infarction.- Valvular Heart Disease.- Thyrotoxicosis.- Alcohol.- Metabolic Causes of Atrial Fibrillation.- The Role of the Autonomic Nervous System in Precipitating Atrial Fibrillation.- Physical Factors Precipitating Atrial Fibrillation.- Iatrogenic Atrial Fibrillation.- Self-Induced Atrial Fibrillation.- Congenital and Familial Causes of Atrial Fibrillation.- Infection and Infestation.- Malignancy.- Connective Tissue Disorders.- The Acute Abdomen.- Neurological Conditions.- Respiratory and Sundry Conditions.- Spontaneous Termination of Atrial Fibrillation.- Thromboembolism.- Prevalence of Thromboembolism in Atrial Fibrillation.- Prevalence of Atrial Fibrillation in Thromboembolism.- Prevalence of Stroke in Atrial Fibrillation.- The Prevalence of Atrial Fibrillation in Stroke.- Intracardiac Thrombi in Atrial Fibrillation.- 10 The Management of Atrial Fibrillation.- Presentation.- Symptoms.- Signs.- Investigations.- General Management.- Control of Ventricular Rate.- Digitalis.- Beta-adrenergic Blockers.- Calcium Antagonists.- Cardioversion.- Selection of Patients for Cardioversion.- Complications of Cardioversion.- Physiological Consequences of Cardioversion.- Long-Term Results of Cardioversion.- Chemical Cardioversion and Prevention of Atrial Fibrillation.- Quinidine.- Calcium Antagonists.- Disopyramide.- Propafenone.- Digoxin.- Beta-adrenergic Blockers.- Amiodarone.- Flecainide and Other Class 1 Agents.- Anticoagulant Therapy.- Rheumatic Valve Disease.- Non-rheumatic Atrial Fibrillation.- Cardioversion.- The Wolff-Parkinson-White Syndrome.- New and Experimental Techniques in Atrial Fibrillation Pacing.- Internal Cardioversion.- His Bundle Ablation.- Surgical Treatment for Atrial Fibrillation.- Appendix. A Simple Computer Model of the Electrophysiological System of the Heart, Considering the Sinoatrial and Atrioventricular Nodes as Sine Wave Oscillators.