NINA S. BRAUNWALD RESEARCH FELLOWSHIP

Jennifer Dale Walker, M.D., Medical University of South Carolina

Dr. Walker is a third-year resident in general surgery, whose thesis concerns the evaluation of the thyroid hormone triiodothyronine, which has been shown to improve the left ventricular pump function. It has been suggested that T3 may have potential therapeutic value for patients with LV dysfunction. The use of thyroid hormone may have particular clinical importance with respect to cardiothoracic surgery, where the number of elderly patients with advanced cardiac disease and patients undergoing reoperation have continued to increase. This research proposal provides a logical and concise progression of basic research studies of the potential for using thyroid hormone as an inotropic agent as well as the basic mechanisms of its actions. A cardiothoracic laboratory at the University has focused upon the relationship of myocyte structure and function to overall ventricular performance. Accordingly, a specific objective of this will be to define the direct effects of thyroid hormone upon myocyte structure and contractile performance. A second objective of this project will be to determine the direct effects of acute thyroid hormone administration upon myocyte function following hypothermic cardioplegic arrest.

THE THORACIC SURGERY FOUNDATION

RESEARCH FELLOWSHIP

Julie R. Glasson, M.D., Stanford University Medical Center

Dr. Glasson is a second-year resident in general surgery, whose project addresses "severing the chordae tendineae during mitral valve replacement [which] has been shown to have deleterious effects of cardiac function. We plan to investigate novel mechanisms responsible for this observation. We will also study alterations in the biochemistry of cardiac muscle as left ventricular function changes over time following mitral valve replacement. The results of this study will provide an understanding of the role of the mitral valve apparatus, both in maintaining LV function in normal hearts and in improving LV function in abnormal hearts with chronic mitral regurgitation following mitral valve replacement. We expect to find that role to be a significant one, involving complex geometric alteration in the shape of the LV. At the conclusion of this project, we hope to discover a scientific rationale for utilizing chordal-sparing techniques during MVR and to provide a better understanding of the mechanisms by which the LV compensates for chronic mitral regurgitation."