But based on earlier work showing that whatever leads to heart failure it is always preceded by changes in the heart cells, a new study demonstrates that a moderate dose of thyroid hormones (TH) over 30 days "normalizes" the shape of the cardiac cells (myocytes) and reduces stress on the heart's wall nearly 40%.

"As patients move toward heart failure, the myocytes become longer and flatter, and the wall stress worsens," according to the head of the laboratory where the research was performed. "But moderate TH therapy selectively targeted myocyte cross-sectional shape and modified it in a positive way.

This is the first clue on what might be a novel therapeutic approach to heart failure because of the return to a more normal heart cell shape," according to A. Martin Gerdes, director of the Cardiovascular Research Institute, University of South Dakota.

The study, entitled "Thyroid hormones induce unique and potentially beneficial changes in cardiac myocyte shape in hypertensive rats near heart failure," appears in the May issue of the American Journal of Physiology-Heart and Circulatory Physiology, published by the American Physiological Society. The research was conducted by Tracy A. Thomas, James A. Kuzman, Brent E. Anderson, Susan M. K. Andersen, Evelyn H. Schlenker, Maurice S. Holder and A. Martin Gerdes.

More animal testing needed before move to humans

Based on positive preliminary findings, the University of South Dakota-Florida A&M University research paper reports that moderate TH positively affected heart remodeling and reduced wall stress in ways warranting further study. However the authors warn that since the mechanism of thyroid hormone influence on diseased hearts isn't known, continuous TH therapy could endang
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12-May-2005