Models and Measurements of the Cardiac Electric Field

ISBN-13: 9781468442465 / Angielski / Miękka / 2012 / 232 str.

E. Schubert

Opis

The electric field of the heart was described diagrammatically for the first time by A. Waller in 1888. However, it was not until a little more than ten years ago that with the development of micro electronic techniques, it became accessible to biophysical modeling, to exact physiological measurements, and to application in advanced clinical diagnosis. These possibilities opened the way to the treatment of questions which are called the direct and the inverse solution of the cardioelectric problem. Several groups of investigators are now working to achieve a complete biophysical and physiological description of the generation of the cardiac electric field. This work could well form the basis for a new method of diagnostic measurements, with applications even in clinical cardiology, delivering important information by a non invasive investigation of the patient. Several conferences have stimulated international exchange of the results of research on the cardiac electric field. Among others, the satellite symposium of the XXV International Congress of Physio logical Sciences on the electric field of the heart, in Brussels, August 2-3, 1971, and the Conference on Measuring and Modeling of the cardiac electric field, in Smolenice near Bratislava, June 14- 17, 1976, may be considered predecessors of the Dresden symposium the proceedings of which are presented in this volume."

Spis treści

Introductory Review.- Electrocardiography and Magnetocardiography Today.- Mathematical and Physical Modelling of the Cardiac Electric Field.- Heuristical Algorithm for the Correct Solution of the Inverse Problem in Terms of the Model of a Closed Electrical Double Layer.- The Inverse Potential Problem Applied to the Human Case.- Computer Simulation of Cardiac Excitation.- About the Accuracy of the Method of Calculating Integral Characteristics of the Cardiac Electrical Generator.- An Attempt to Localize the Pre-Excitation Site in Wolff-Parkinson-White Patients by Means of a Mathematical Model.- Local-Integral Characteristics of the Cardiac Electrical Generator Based upon the Multipole Expansion of the Potential.- A Mathematical Model of the Equivalent Magnetic Cardiac Generator.- Factors Influencing the ST-Segment Mapping Evaluation (A Model Study).- Model Study of the Lead System Influence on the Image of the Physical Equivalent Generator.- Measurements in the Cardiac Electric Field.- Problems and Trends in Body Surface Mapping of Bioelectric Fields.- A System to Standardize and Analyse Surface Measurements for Model Fitting.- Tridimensional Distribution of Heart Potentials After Endocardial Stimulation.- Quantitative Evaluation of Body Surface Maps in Normal and Pathological Conditions.- A Comparison of Orthogonal Lead System Vectors Using Different Equivalent Dipole Generators.- Physiological Influences upon the Dynamics of Surface Maps During ST-T: Effects of Varied Heart Rate.- Problems of Comparative Electrocardiology Created by the Progress in Computer Mapping of the Cardioelectric Field.- The Electrical Resistivity of Lung Tissue Filled Either with Air or with Fluid.- Estimation of Cardiac Excitation on the Basis of Stimulus Response Functions and Epicardial Activation Isochrones.- Epicardial ST-Segment Mapping in Acute Myocardial Ischemia. Examples of Coincidental Experimental Interventions which may Affect Interpretation.- Natural History of Experimental Myocardial Ischemia. Observations in Acute and Chronic Studies.- Clinical Applications of Cardiac Electric Field Mapping.- Axis Concept in Body Surface Mapping.- On-Line ECG Mapping by a Small Microprocessor System.- Methods for Automatic Classification in Body Surface Mapping.- Exercise Electrocardiography and Monitoring of Myocardial Infarction with a Clinical Mapping System.- Surface Mapping Characteristics of Left Fascicular Blocks.- Spatial Velocity in the Second Part of QRS in the ECG of Rabbits.- List of Contributors.