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Handbook of Electrogastrography
Kenneth L. Koch, Robert M. Stern
The Handbook of Electrogastrography is the first textbook dedicated to reviewing the physiology of gastric myelectrical activity and the measurement of this electrical activity with electrodes placed on the abdominal surface - the electrogastrogram. The Handbook is divided into three major sections. The first section focuses on the history of electrogastrography, electrical activity of the interstitial cells of Cajal, the cells from which gastric electrical rhythmicity emanates. The cellular level of gastric electrical rhythmicity provides an understanding of the physiological basis of the electrogastrogram signal. The second section of the book incorporates the practical aspects of recording a high quality electrogastrogram and approaches to the analysis of the electrogastrogram using visual inspection and computer techniques. This section focuses on the authors' combined experience of examining EGG recordings for more than sixty years. From this rich research and clinical experience, the clinical application of EGG recordings in an approach to patients with unexplained nausea and vomiting is described.; Neuromuscular disorders of the stomach involving gastric dysrhythmias are reviewed. The third section of the book comprises many examples of gastric dysrythmias ranging from bradygastrias to tachygastrias and mixed dysrythmias. Current understanding of the mechanisms of gastric dysrhythmias is reviewed. Artifacts in the EGG signal, which may be confused with gastric dysrhythmias, are also presented. The Handbook of Electrogastrography will be a valuable reference for physicians interested in recording gastric electrical activity in clinical practices or in clinical research. Gastroenterologists, internists, psychologists and others with an interest in gastric myoelectrical events will also find extensive and relevant information for recording and interpreting EGGs in the Handbook.
Contents
1. Brief History of Electrogastrography, 1
Robert M. Stern
2. Properties of Electrical Rhythmicity in the Stomach, 13
Kenton M. Sanders, Tamas Or dog, Sang Don Koh, Sean M. Ward
Properties of Gastric Electrical Slow Waves, 15
The Slow Wave Frequency Gradient, 17
Characteristics of Slow Wave Propagation, 19
Pacemaker Currents Generated by Interstitial Cells of Cajal, 20
Mechanism of Pacemaker Activity, 22
Regulation of Pacemaker Frequency, 24
Basis of Some Gastric Dysrhythmias, 27
Cautions for the Use of Electrogastrography to Evaluate Gastric Arrhythmias, 32
3. Physiological Basis of Electrogastrography, 37
Kenneth L. Koch
Gastric Pacesetter Potentials and Action Potentials, 37
Normal Electrogastrographic Patterns in Healthy Subjects, 45
Fasting Electrogastrographic Patterns, 45
Postprandial Electrogastrographic Patterns, 47
4. Recording the Electrogastrogram, 69
Robert M. Stern
Equipment, 70
Electrodes, 70
Recording Equipment, 70
Recording Procedure, 70
Electrode Placement, 70
Procedure, 73
How to Minimize and Identify Artifacts, 73
Movement of the Limbs and Body, 73
Talking, 74
Identifying Artifacts in the Electrogastrographic Signal, 74
Electrode and Other Electrical Failures, 74
Respiratory Artifacts, 74
Harmonics, 78
5. Analysis of the Electrogastrogram, 83 Robert M. Stern
Visual Analysis of the Electrogastrographic Signal, 83
Computer Analysis of the Electrogastrographic Signal, 84
Filters and the Electrogastrographic Signal, 87
Spectral Analysis of the Electrogastrographic Signal, 87
Running Spectral Analysis (RSA), 88
Specific Electrogastrographic Parameters, 96
6. Clinical Applications of Electrogastrography, 101
Kenneth L. Koch
An Approach to the Patient with Dyspepsia Symptoms, 102
Gastric Neuromuscular Dysfunction and Dyspepsia, 106
The Electrogastrogram and Water Load Test, 106
Treatment of Gastric Neuromuscular Disorders Based on
Pathophysiological Categories, 125
Clinical Applications of Electrogastrography in
Pediatrics and Obstetrics, 139
Applications of Electrogastrography in Research, 142
7. Tachygastrias, 149
Kenneth L. Koch
Pathophysiology of Gastric Dysrhythmias, 149
Origin of Tachygastrias, 151
Tachygastrias, 159
Tachygastrias (Unifocal), 160
Tachygastrias (Diffuse), 169
Tachygastrias (Probable), 175
Fictitious Tachygastrias, 178 8. Bradygastrias and Mixed Dysrhythmias, 185
Kenneth L. Koch
Origin of Bradygastrias, 185
Slow-Frequency Contractions of Antrum and Fundus, 185
Temperature of Intragastric Content, 186
Intragastric Volume, 189
Distention of Antrum, 189
Transection of the Gastric Corpus and Bradygastria, 193
Colonic and Small Intestinal Myoelectrical Activity, 193
Movements of the Body and Limbs of the Subject, 194 Bradygastrias, 194
Bradygastria (High Amplitude), 194
Bradygastria (Low Amplitude), 198
Mixed Gastric Dysrhythmias, 200
9. The Future and Electrogastrography, 213
Kenneth L. Koch and Robert M. Stern |
