REFERENCE FRAME FREE LEFT VENTRICULAR SHAPE, THE TANGENT ANGLE FUNCTION, AND CORONARY ARTERY DISEASE.
Item
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Title
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REFERENCE FRAME FREE LEFT VENTRICULAR SHAPE, THE TANGENT ANGLE FUNCTION, AND CORONARY ARTERY DISEASE.
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Identifier
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AAI8319753
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identifier
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8319753
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Creator
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COHEN, MARK LIST.
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Contributor
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Harry Smith
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Date
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1983
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Language
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English
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Publisher
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City University of New York.
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Subject
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Biophysics, Medical
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Abstract
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The outline of the cavity of the left ventricle of the heart is visualized during cardiac catheterization. Despite the almost routine use of this technique, there is no consensus as to how the two-dimensional outline is to be analyzed. This is because all current methods attempt to measure wall motion: a measurement that, in its definition, requires the use of conceptually unverifiable assumptions about the motion of the heart.;In this dissertation, shape and shape change are presented as alternatives to wall motion. The tangent angle function is shown to be a measure of shape that involves no assumptions about the motion of the heart and that has interesting interpretations in the setting of coronary artery disease.;The tangent angle function was applied to the end diastolic and end systolic outlines of the hearts of patients who had isolated single vessel coronary artery disease, or no coronary artery disease. The tangent angle functions were parameterized and, using discriminant analysis, combined into two canonical variables. These were shown to abstract end systolic dysfunction with compensation, and total systolic shape change. Using a jackknife, 70% of the patients were allocated to the correct coronary artery group using the shape-derived canonical variables. This was verified with an independent set of test data.;The reproducibility of this approach was assessed with an additional independent set of test data, and with a study of the variability in transferring the outlines from the catheterization films to the computer. Both these studies showed considerable variability with respect to the initial results, indicating that additional quality control and study of the patient population is necessary before the method can be used clinically.;It is concluded that shape and shape change are useful alternatives to wall motion in the study of the left ventricular outline. The combining of parameters of shape offers interesting insights into the response of the left ventricle to coronary artery disease. Extensions to other areas of application in clinical cardiology and to the methodology are discussed. The reliability of the data, and the possibility that the patient population and catheterization techniques did not remain standard, are identified as major limitations.
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Type
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dissertation
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Source
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PQT Legacy CUNY.xlsx
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degree
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Ph.D.
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Program
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Biomedical Sciences
